Modern Steel Products (2015) - lecture 7


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Modern Steel Products (2015) - lecture 7
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7 (2015)
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Cooman, Bruno C. de
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A series of lectures on steels, given by Professor Bruno de Cooman, Graduate Institute of Ferrous Technology (GIFT), POSTECH, Republic of Korea
Gedeckter Güterwagen Fur clothing Computer animation Steel File (tool) Hot isostatic pressing
Vertical stabilizer Kit car Tin can Hot working Lint (software) Ford Transit File (tool) Printing Playground slide Rigging Computer animation Ship class Spant Typesetting Spare part Remotely operated underwater vehicle Book design Steel Wärmebehandlung Steel Ship of the line Transmission (mechanics) Miner Engine control unit
Cut (gems) Vise Gedeckter Güterwagen Game Sizing Computer animation Worm drive Avro Canada CF-105 Arrow Photographic processing Internal combustion engine Steel Material Gun
Matrix (printing) Hot working Tracing paper Hull (watercraft) Scouting Forging Screw Roll forming Mechanical watch Sewing needle Spare part Surface mining Steel Material Photographic plate Schlicker Truck Hot working File (tool) Cord (unit) Toilet paper Texturizing Computer animation Wood Microform Work hardening Estudio Lamela Totholz <Schiffbau> Rail profile Ship of the line Steel Workshop Engine control unit Last
Clock Hüttenindustrie Blast furnace Roll forming Turning Automobile Tool Negation Steel Material Blast furnace Typesetting Stagecoach Hot working Machining Bending (metalworking) Machine Sizing Computer animation Cartridge (firearms) Work hardening Totholz <Schiffbau> Wärmebehandlung Material Ship of the line Steel Tanning
Typesetting Hüttenindustrie Railway Mail Service Casting defect Surfboard Cougar Silvering Screw Roll forming Gemstone Computer animation Mechanical watch Automobile Photographic processing Alcohol proof Spare part Klassifikationsgesellschaft Steel Engine Material Steel Material
Friction Hot working Electric resistance welding Scouting Sewing Casting defect Bloomery Saw Sheet metal Mechanical watch Doorbell Spare part Rolling (metalworking) Steel Kupferbarren Material Giant (mythology) Matrix (printing) Photographic plate Truck Connecting rod Ramjet Coating Mechanic Vacuum pump Wire Ampoule Finishing (textiles) Electric locomotive Cord (unit) Clothing sizes Chemical substance Glasfluss Computer animation Screw Crown (headgear) Cartridge (firearms) Casting Fuel economy in automobiles Plating Wire Material Steel Sheet metal Friction Gun
Electric resistance welding Commercial vehicle Distribution board Vehicle Printing press Casting defect Roll forming Sheet metal Packaging and labeling Sewing machine Mining Steel Guard rail Stool (seat) Engine Material Matrix (printing) Cylinder block Photographic plate Tin can Vacuum pump Commercial vehicle Intermediate bulk container Finishing (textiles) Texturizing Glasfluss Computer animation Rolling (metalworking) Screw Surface mining Train Fuel economy in automobiles Cardboard (paper product) Packaging and labeling Rolling (metalworking) Steel Sheet metal Pocket watch
Semi-finished casting products Jet (lignite) Insect wing File (tool) Cord (unit) Sommerreifen Automobile Spring (device) Continuous casting Mining Steel Material Typesetting Mat Semi-finished casting products Connecting rod Ballpoint pen Wire Cord (unit) Paper Chemical substance Fulling Computer animation Cartridge (firearms) Mint-made errors Wire Steel Flatcar Holzfaserplatte
Nut (hardware) Semi-solid metal casting Kran Schienenkran Bergwerksschacht Belt (mechanical) Welding Gear Alcohol proof Continuous track Collar (clothing) Tool Steel Engine Satellite Material Aerial tramway Typesetting Nut (hardware) Truck Spindle (textiles) Connecting rod Ramjet Wellen-Naben-Verbindung Handwagen Rapid transit Ballpoint pen Wire Gear Machining Train Common rail Computer animation Screw Drill Cartridge (firearms) Wear Guard rail Welding Caliber Rail profile Book design Steering Wire Wärmebehandlung Steel Front-wheel drive
Verzinnen Chemical substance Silk Connecting rod Hot working Structural steel Piston Machine Food packaging Gas compressor Watercraft Roll forming Computer animation Mountain Spare part Spare part Klassifikationsgesellschaft Steel Single-cylinder engine Steering Ship of the line Steel Last Kurbelwelle
Chemical substance Connecting rod Structural steel Piston Computer animation Cartridge (firearms) Spare part Spare part Klassifikationsgesellschaft Steel Material Water vapor Kurbelwelle
Game Computer animation Hüttenindustrie Steel Material File (tool) International Space Station
we 2 some good morning I'd like to
remind you of the
fact that we missed 2 lectures the 1st week of the semester so will allow we will have some makeup that I would like to have him this week so I was thinking of doing Friday said he would have lectures on Friday morning what would english what about Friday afternoon and then do them on Friday afternoon election or at what time of and then there was the question last alone and I have to plants which will like to come back true the kiss anybody else's to come
from the Suwit following elements at the
effect of polynomials transformations so this
is preparedness to slides this morning and that their own data the class of the
you I want to work print amount to something that is so just just wanted to make sure you understood what to I
declare chrome and Molly do 1 when you added at the to the 2 steal subsidy I take for instance here you have a steel with about 20 30 per cent of the car and that this is a transformation normally the transformations are really fast certainly with low carbon contents you go really fast transformation so that this is here if a little if you see it clearly that this this is half a 2nd book a half-second that's very fast and you can see here that this seeker of Florida started the transformation this is shorter than half-a-second so almost immediately as you cool down you've you'll start forming answers if if this is a T T T diagrams sits the way you have to think about it you you are in the Austinite you go to a certain temperature and you look at the transformation I so thoroughly yes and you can see here are you know from from the relatively long time but I say after the about a day here the other a few hours To me to say this about an hour 2 hours 3 hours 3 hours you cool down and it's all transformed too verite and Pearline candidates that's that's what 2 . the the information in that diagram tells you know it you to you take this same steel now and you add about 2 per cent of chrome two-way trade so and I've taken this this this seeker of here this the year is the curves that tells you the 50 per cent this transform 50 per cent of the Microsoft is transformed so it wouldn't appear and you can now see that the transformation 50 percent transformation line has been pushed back this so all the transformations have been slow down yes that's 1 thing and and and and then there is another feature that's interesting that you get what is called a transformation Bay the incident means if the if now I do the transformation the transit at a temperature where the transmission is really fast it turns out that now it's art groups and it's it's gotten much slower 10 that's what we call transformation bait when you add the use of credit forming elements such as chromium and knowledge so bad and you're on top you form pro-life and right and perlite but end so you can see here that the Soviets had the transformations for fair yes this is still there he knew that doesn't start very much later but the kind that Texas has slowed down considerably it's enough to take some of that pessimism started that same time but it could takes much longer time to get a transformation go and and and a transformation Bay but below the transformation that you basically get the nite transformation gay and so this is 1 per cent of and this is what 1 .period almost 2 Percent of molybdenum you basically saying that the general has the same effect maybe even stronger than that you push back to transformation now 1 of the things that's that's different here is that you see here Austinite it's stable in this region here when you add chromium when you add molybdenum yes there is no transformation at all yes so now not only is the transformation slower but it also takes a long time before it starts the OK so that that if you look carefully also said this was the 15th the Percent transformation you see here that the bay nite transformation has I at the same temperature this isn't influenced very much of course it's got it's gotten slower because that was the 50 Percent line and a 50 percent line is now here but you're basically going from in on 2 to 3 seconds to 20 seconds at its yes but a lot much more so but you definitely see that the Beihai transformation well be however I I prefer to go by the molybdenum additions and of course if I do a nice eternal transformation from here to here I'm not going to get any brain nite anyway writes that something that still states decide OK but gets so that's why it's important to when when you want to look at the balloting additions to 2 think about I but the transformations the diagrams but also to look to think about what kind of heat treatment you're reply to for instance year this is the same allies the original following this is this the 50 percent transformation curves began I wanted to point out the fact that the verite transformation already starts here this is just a 50 percent transformation line but this is the same line now I've added 1 per cent of gross 1 per cent of Molly and you can see here that's the Austinite stability range is now here yeah combination of the chrome and the Molly really slows down the reactions right reaction the perlite reaction what does this mean in terms of Francis continuous Kulik says that these the DTI Grant a very useful From fundamental point of view because you're looking at ISO he treatments but but in practice for instance where we have a massive piece of steel which we want to keep to read the heating rates the calling rates of very different different positions in that part so TGT diagram hasn't limited usefulness Minnesota disability TT diagram here for it to certain complex deal here which also contains 1 per cent of chrome and 1 one-percent of modern right and as you as you can compared these 2 diagrams has the skills of not exactly the same but as so you see it again under the 50 % transformation line has this day yes above the bay you have far-right and perlite formation below debate you have a big nite for me but if you do continue schooling yes you cannot use this diagram you cannot use the tete-a-tete there you have to use a C C T diagram and there you basically track you have to choose a cooling rates friends we use this cooling rain in this diagram tells me that here I started transformation 2 verite there is 40 % To the 10 per cent is transformed to fair right here and then wait start making a a little bit about perlite there's the the total transformation at it's at this point here is 70 percent good and then as I continue cooling down due in this I'm basically going through this transformation may there is no transformation for a while yes the transformation worse than a transformation starts again at a lower temperature it's urbane nite transformation and then we go to another 30 per cent of volume is transformed to they knocked us new pulled up write to hopelessness the the clear so now
let's continue where
we were where we ended last week and we've been
talking about the grain
size reductions and how this was done with through
mechanical processing
and so on I think we're nice we were talking about the fact that in many steals that this news is structural steels of particularly once did use the construction industry will buildings there the basic strengthening is by carbon but but would you actually strengthening the steel where it is with this perlite like when you add carbon you increase the amount of harbor the Carbide's in the perlite increase the amount of volume fraction of of perlite and and that makes this steel real strong so it's there and then it's very much a composite the perlite itself to this very strong Seaman tied and much softer verite and the maximum UTS you have is about a giggle capacity we saw this here when you have 100 per cent pro-life have a agreed upon so and I had just finished a lecture by saying that if you want to have a larger strains with perlite that's possible however that he is very high carbon content makes these materials very difficult well that's 1 thing and then the other thing is that the way you would make this relied very strong would be by reducing the Inter Lamela spacing desk and technologically you can do this but usually for wireline products so if you want to make cheap products it's you can't really work with with high levels of perlite and you have to think about other methods to change to Microsoft rapture and to get very high strengths and it turns out that you can which deals but at you very high strength with very low carbon contents also so that's the way in which the new product development goes these days but let's say
a a few things about this and that the effect of carbon have so if we increase the the carbon content that we increase the amount of perlite as you can see it less than if I have high poll new tech carbon content less than . 77 are matrix is basically ferret soft I if I have more then .period 77 in carbon now that you can see here I have a hard brittle grain boundary Seaman tightened and most of the microscopic Sperling aggressive the Microsoft really so because we've added This is very high levels of with higher levels of carbon I increased the amount of perlite and like serve as the yield strength increasing I see the tensile strength increasing yes I am but the 1 I see is that it the illumination goes down and and the toughness of the material goes down toughness measured as the impact energy but when you're doing the shopping tests which we talk about that later if you're not familiar with shopping so and so this is another way of presenting this increase in hardness is that of you add pro-life you get more hardness and define a deeper harden the perlite is that's the way you basically increased the strength of a prolific still need to refine the MicroStrategy very small Inter Lamela spacings as if you have cost per line strength this lesson if you have several died where they do the carbide is present not in the Pearl of it as a separate spherical seamen died the material is even softer and with the advantage of course is 1 thinks softer usually more Doctor the impact of the modern society yes you can make at all these carbon contents and all these carbon content you can make a mark on site you can quench material and you find that you can have a tremendous increase in strength here again and the problem when this very high level of strength is that because you get it from supersaturated stood carbon that the material is Brett has doesn't really have any much form ability and so is much stronger than the because the same material With variety perlite mixture and these there and you can see this this is a larger range of carbon content is used as it is used in practice practices the Francis files you than which if you know what a something too smooth metal wood and metal file it's like something like this and it has all these teams like this so you can filed down .period object and he's a very very high carbon steels almost 1 . 5 per cent of the column very very hard market site In the but it's so while and and and their use you know basically this approach you have huge amount of carbon and Super saturation very strong material but in many applications it doesn't work it doesn't work with you to you do you want some of plasticity form abilities of so 1 of the ways you can do this is by tempering the inside but when you do that the material becomes softer as you this is the tempering temperature you can see the yield strength goes down tensile strength and the reduction of area if you if you will the measure due reduction of the section at oversampled increases and what happens is during the tampering here you see a laugh Martin site Mike rastructure these are the last of the mark inside and you see it is that all little spectacles in the like the structure that's not etching effect while it is enacting effect but these are basically a small Carbide's that our form in the mike rastructure when the carbon goes out of solid solution to a very small part so In conclusion the Austinite as a rule you know you can call it slowly with moderately of cooling rapidly if you do a rapid quenching the market side usually reheated to obtain tempered Martin site would verify Carbide's which allows you to get very hard material that's does have some toughness moderate cooling will give you may 9th again as did my perspective it's very similar to that of of Martin side but the during a transformation you do have motion of the carbon carbon can diffuse during the day and nite and if you do a relatively slow cooling you get either a variety of far-right political like rastructure and most of the steals that we use our hype will you take toilets you get pro Utica torrid affair rise in the Microsoft truck and as a rule you can you can say for Martin cited stronger than tempered market they I find for life cost per spelled out right that might
rastructure is that are produced during processing of steel as I can be In the state of constraints sold and that's basically the big difference between hot working and cold working when you hot work a material written in a hot strip mill you get mature over crystallizes it takes less energy to deform at high temperature there may be some oxidation has and material has lost strength and that usually after processing of high temperature you have you material 3 Crystal it's not the case with cold working there's no way crystallization in general so it takes more energy to before his last oxidation of surface so that means that products at a cold deformed usually have a very good surface finish that's also the reason why and we do a cold deformation because of the surface finish and control Of the dimensions of the product we have increased strength you get cold work might rastructure such as the micrograph here and which are an isotropic meaning that there is list isotropic of properties is usually the result of texture of crystallographic texture being created so you can see the continued until the grains and you can see slip lines in these slipped traces in these grains that tell you that this is the Cold War Mike rastructure In this is a
MicroStrategy here where you can see the grain this is hot rolled Mike rastructure many stainless steels but when they're hopped on public forms do not really crystallize very well so in this particular case is an example of a sop to work at the mike restricted that is not free crystallized so after annealing these very fine grains and the highly deformed hand grains are replaced by more acquiesced drains and you can see here so you need but we crystallization and
we crystallization is we crystallization and kneeling is 1 of the heat treatments that we the plot during the processes that we generally referred to as annealing In you have to be very careful in the way when you use the word than dealing are you hear the word and kneeling in reference to steal specific many different things that can mean many different things I hope so as so annealing you'd basically he too material obvious deal about certain temperature in you hold it for a certain time before cooling there so that all these the parameters that may seem obvious but the taking rate the holding time soaking temperature and a cooling rates are all important parameter yes and it will give you a variety of microphone so that different types of annealing stress relief and healing it reduces stress is caused by plastic deformation a non-uniform cooling and face transformation I would this distress relief to it's basically I'm in from them physical metal achieved prospective point of view you basically reduce internal stresses which are present in the material by recovery processes to you the recovery process is a process whereby you rearrange the dislocations in energy configuration the that's the only motivation and you you already know the system in very soft steals stews that normally would contain pro-life why would you make that while too make the plastic deformation easier easy machining has annually in distillate has just below the EU tech toy temperature for a very long time because it takes a long time to as Pharaoh dies the the buyers and also takes a very long time because you cannot go to higher temperatures could go to a higher temperature you would basically dissolved the Carbide's and so nothing would happen Fulham but makes steel good for forming but by heating and cooling it's being a furnace to to get cost per line normalization is a very important so D the steel uh properties depend on grain size you can refine the grain size by going through a transformation and back when you create a new tool that allows you to have get smaller uniform brains and you also have processed Neil which is basically removing the recovery crystallization and yelling you removed the negative effects of cold working by a recovery usually by for a crystallization so of this is that basically the the big difference if I look at the bottom firing rates side of the island :colon diagram and normalization involves full transformation I so you go over the 81 temperature don't forget that if if this is a fast normalization has the 83 temperature has to be you have to go higher than this temperature because the since the reading this will be higher than the 3 of do you know that this would be a city authorities temperatures can and be so on you can have made a process and he'll then you really he did material up so it would crystallizes but it you don't want it to transform right so you keep the temperature 2 the 81 instant or once you know 1 transformation just 1 we crystallization of the far-right foreigners so sold and usually that's a pretty rapid process remember because it takes only 1 of the order of seconds to to get the material for the deformed variety would crystallize so it was pretty rapidly the EU here distress relieved only requires recovery so if you don't go to very high temperatures because you don't want to achieve Richter isolation and finally sterilize Sparrow diarization requires a very long time at a temperature right below the 1 again you cannot go higher because then you dissolve your car but that's why you have to say at this temperature that's also 1 of the reasons why it takes such a law time at this stage we thumbs general discussion about you know the physical analogy that we need to know for the costs so you have some general things about compositions and crystal structure and transformation relationship between Mike rastructure strength and so on and I will be able to use this whenever we discuss the processing of steels technical processing of steel and the composition of Austinite comes into the picture of and that will help us understand why you use particular industrial processing parameters and and not all the ones but so the we it
continue now with the idea
another small introductory the
part which is about steel standards because we need to know is a few things about
steals and steel standards for their so you you little bit more familiar with Tom using the names of materials so as some of EUR in research yes but most of the materials that you know you're you're dealing with ah non-technical materials silver alloys that you make yourself yes for for research purposes in the real world it's very different you're not supposed to be to create a right is supposed to you know when still needs to be produced in large amount it's according to a standard that and even if you're very smart yes you're not allowed to do experiments on production and that's very important to realize that you know the steel centers are extremely important in process because they identify a steel and it guarantees product quality and real liability and interchangeability and usually there's a coherent as simple and convenient way and they provide a specific name under the form of symbols numbers letters or combinations of these that allow you the engineer to see but you know what is the composition of the material with odd chemical properties that are certified when I clients purchase that material OK so will say a few things about that down and and don't forget the the Force Research does have influence on the standards but there much more controlled by professional engineering engineering societies trade associations government read regulatory bodies etc. rather than by research again so I'll do whatever we can to all the metals and alloys are subject to the same type of standardization and and so we know what we were talking about today are the ferrous alloys and the ones that contain less than 2 per cent of cars that we not talk about cast irons or other I found out and
all these products here 2 plates sheets sections Bara wires etc. when a customer purchases these dance it's always according to specifications so what does that mean that the composition of course thermal processing chemical processing and very much important are application properties that guarantees the grade of the properties that go along with the great specifications and that can cover a very wide a product-specific is can cover a very wide array of elements so not only the mechanical properties in composition but know can be geometrical properties to your product dimensions the shape of the product they can be the certain cases Microsoft truck troll properties requirements composition is 1 of them and they can be on the technical requirements for instance Weld ability phosphate ability probability roughness friction and in certain cases magnetic or electrical problem right so let me let me give you an example all the let me know if you just go
back to suspect that these requirements here they're going to the product they are produced in plants and in by combination of course industrial plant of the approach to processing raw materials that use the way you control and on 2 major property or your product and of course in the steel industry very important the IT infrastructure because it's a very highly "quotation mark maintenance industry so they're usually in Europe in the great specifications performance is important so an engineer but that but requires steel for building guest will need certain mechanical properties yes which numbers as France's will have a minimum yield strength of this much yes and the specifies this that property that number it rather it is a property these mega Pascal of the related to strength as for instance this strange is related to the MicroStrategy of new material and depending on the situation can be different parts of the microscope and a combination of this and is my constructor is obtained by processing images that so let's have a look at an example of how does this work but these are these are great specific technical requirements
let's have an example for instance found that a client may be automotive company and automotive company purchases the steel for instance press me as for press so they will require specific Our values remember what our value as the ratio of the West To be thickness strange if you make a tensile sample out of a sheet of material so that's that company Will will say I want this are valued minimum 1 . 5 million so that means said anything that you as a steelmaker of supply if a random sample is taken the R value has to be 1 . 5 minimum yes now that is a form ability property yes it is it has nothing to do with with hardness or or strength it's a affordability ability property the structure its In terms of the structure it's related to Crystal a graphic picture yes and in the process yes vacuum the gassing plays a role in this crystallographic texture the Alloy Inc plays a role the cold rolling and the annealing process play a role in obtaining the rights former ability to length for the parameter and allowing for parameter in such apply this is what we call steel design so if you have a client it's a maker who has a problem makes this making of pressing panels and there's some cracks in the panel has a new client that makes the task and it turns out that is R value the material doesn't have the aura of value that you promised yes you can explain do all kinds of explaining you want yes Maturin trouble yes because you didn't provide material according to specifications yes and it doesn't matter how much science you have yes it's if it's not according to specifications you can take back the material and you can pay for all the damage that you've caused decline yes the specifications art or not the laughing matter is very important us so what
what form does this stake in practice OK while the system for instance a specification yes I'm it's early on called by world coil here it's ready for shipping to and from production is what can we learn from the label yes so it's sad a wallet-size where it's going to but you can also see paid by Posco and then the steel it says the steel it says the dimensions of this deal yes and the weight of the court 11 talks 11 5 of the 30 people so that it says Jess G. 31 31 pete H C that's that's the great yes and attached to this great or a lot of specifications you so just this very common in Asia because it's very well vary widely used Japanese steel great name S & L it's 1 G 31 31 is the it's at the center reference if you want so it's it's for it's the reference document for hot the rolled mild steels and sp stands for for S stands were steel peak for playing carbon H for hot rolled and see for commercial quality so that means it's a steel with regular properties as of it's very important that I you realize that even tho this is not a very special steel has and it does cost Money so it costs about 620 dollars per through Correa like this you know easily goes into the thousands of dollars yes and it's a very basic quality and there are additional costs of course for you know who pays for it transportation and for the insurance etc. OK so let's have a look now once we have a specification to light like this 1 this is a very common structural steel it does not contain special alloys and additions that's usually with means by this commercial quality so in Japan we have this great name In the West we have the equivalent grade has another name and in Europe it's called and as 275 OK and this is the typical compositions you can see the maximum points at 6 manganese .period 15 carbon in terms of the composition it's not a very tough 1 to make that you see another advantage here of the standards this is you can sell products in other countries yes because great specifications can be compared notes and you can identify equivalent grades in different countries now even in the world in general but there like 3 big blocks of Strong standards danger its GI asked in Europe it's and and in North America there it's a little bit complex and lots of engineering and trade associations that have their own a specification was a few things about this but AST M S E the IST the ISI Excuse me are typical of bodies that issues specifications but
another 1 here and now it's on the ballot there's so still products don't have to be finished Basel finished wire or finished cheat the steel industry can sell intermediate products such as slabs or billets all saps flats and villas this is an example here it said it's continuous cast billets now and it also has a sticker here tens and in this particular case is itself a will be used to make quite a robbed and that can then be used to make ball bearings nuts-and-bolts wire tire cord spring it's again you see I'm G 4 1 0 5 so that that's the reference document for this type of steel and then there the great names this year the Senate good and then you have the number SCM and 440 what does this mean again there's lots of information in the in the symbol will 1st of all we know is that Japanese S stands for steel yes but which tells you of course there just is not only about steal it that also has issue standards for aluminum and other materials the C stands for chromium steel and M stands for molybdenum so you can very quickly if you're into in the field you
can see this again and once you know this is a common medium carbon steel and its allied with chromium and molybdenum so we know why we add chrome molybdenum to increase Hardin ability and that's the Bastille conferences be used to make hardened high-strength bowls and seriously bolts this type of bowls of for instance that I used to In in construction and talks a few things how you make these bolts so but again and it was you know the Japanese Standard name you know corresponding 1 in the West and in use in Europe has now you'll seeing eye if you look carefully there is the Jets ends with 40 the Americans in this particular case the Ironside St found specification ends with 14 and the European the normalization for steel has 8 starts with 42 this refers to the carbon content times 100 for the carbon content of this article is steel is about . 4 Pesek European the standard digital code also tells you that's the sea here and the end year or chrome and Molly dissident full chemical symbol is written out in contrast to the Japanese with words you have to know that Siemens crop and then you have an additional number here before yes which gives you more information about the composition in the case of the European normalization scheme so that if you look at this and see . 4 to mass Percent of carbon this symbol is 4 times the the chromium content all tell you the moment white why we multiply divide by 4 and then it also has molybdenum additions I am here but they are not we don't know how much of this is the symbol and that there are other symbols in India in Europe also the number symbols which are equivalent of the SEE why is it that we would don't write 1 % here it's because many times and your you concentrations eloquent trees are followed In steals and they can be like 1 . 5 they can be all . 5 years now when you at purchasing steel yes you have to write a paper lots of paperwork has and you want to avoid making errors yes it is very easy to make errors if you use decimal points for comments and and in order to avoid using decimal point of commerce minister in Europe in these standard issue if we multiply wait a convenient number so that you end up not having to use common sense and in particular like conditions of chromium or molybdenum ore manganese yes the time you you multiply these elements which for that's not so so friends in Europe you have if I say friends steel 22 NMB 5 it means that this is Harbin times 100 so the carbon content is 22 divided by hundreds of spoke 1 to 2 per cent ,comma it contains manganese and boron yes the number always refers to this element to the first one in the role that doesn't refer to borrow yet but you can say you can tell that it contains both manganese and born as special edition now the manganese is like the car but it should reflect the chrome and Molly it's it's multiplied by 4 so that the actual content is 5 divided by 4 is 1 . 2 5 per cent of manganese OK that's what it means and not like I've heard some people say it means 5 ppm of board no there is nothing to do with the war on poverty Frank so so bad
these specifications yes but when you have a piece of material yet it has a composition yes "quotation mark that said the specifications never give you a single composition you get the composition ranges for instance this year is being the composition range for SCM 440 according to Jess OK the new compositions to be within this range and you're below you have typical typical values for a product like this and it this again is it is very widely used type of steel for or many applications has relatively because the high carbon content relatively high carbon you need to be careful when you well this material into some preheating and stress relief after welding but otherwise very widely used for instance to make of bolts has hired you make both with this material you start the company a company like all schools will that produces wire steel will be producing this an example you with the numbers awful 435 so as as to how much carbon is in the incident .period 4 . 35 years but the material has this strength when it's produced 902 1100 maker Pascal so you 1st do soft annealing of this microscope trip so yes and you do this because you want to adjust the diameter of the wire to the diameter you need to make has to to produce books venues Ferro dies then this paradise the Microsoft truck truck this is the realization that the material is not much much softer instead of being 902 with thousands 500 to to 600 megabytes up so you can do cold forming of the y ears you make little pieces of this wire and then you 4 minutes you basically before cold fortunate into a bull yes it's a very soft bolt it doesn't have good mechanical properties of the year yet the batteries low so you were it also the ties at you quench it and then you do it at the temporary to get of some of the toughest back that you have lost if you but you don't have if you have a purely Martin acidic Michael structure that this this is the big step here you use paradise the mike rastructure of this type of steel so that you can called formed bowls with it's a process the sterilization again I want to point out is a process that takes a lot of time and 1 of the reasons why it takes a lot of time for instance in this SCM for 48 USC 35 is the fact that because you have added molybdenum and chromium to make to steal Hardin about the sterilization also takes a long time because the goes into these Carbide's and they will influence the sterilizations kind this is the ball to usually very hard material the nuts is not is is made of different materials yes which has shown here so With specification comes a lot of information also about this material so for instance and once you know the great specifications you can find the the way you have to heat treated material the the client that and so that's another reason why of it's early and engineering steels it's very important to have a to have the specification because the princess who this person this great here as this is the Atsushi diagram so this I bolts maker in that it will have to make the quench and tempering went the quenching and tempering knows that all the critical temperatures that he has to adhere to form a Martin citic microscopic for instance you can see here that the cooling rates when he makes the Baltic cooling rate will have to be of the order of 36 degrees the 2nd best for him to to achieve fully Mark acidic microscope this other
example here is this is in the eye aside 51 20 so again we know that the 15 to 20 years stands for the carbon content and well this is an American on SAT grade has an equivalent just name a S C R 4 22 was so again doesn't come as a surprise to 22 of its 22 carbon SCI R means it's Jess this is steel and Sciorra stands for crop so it's a Crowley added steel with a point 22 carbon so it's going to be used for engineering application this particular case it's it's used to make gears you can see and and the way it's being done and then you start with the ability for instance Scott and forged and machined and then you have heat treatments which can consist of Carver rising to make these people geared to a very Strong and wear resistance the new quenched and and you have this final product here so what's the key addition here is the chromium and and and why is that well because we want Hardin ability want gears to be very strong and so we achieved this by so the 2 examples I found differ on hard ability was important and chromium and molybdenum and their depending on prompt other products you get other emphasis which comes out through in the air In the specification for rails the rails are usually referred to as as a Y C grades and it's a French UIC says what you want to national edition and fair means of international the Union of railroads in and the number for you when you see what see you didn't absolutely always know it's it's a it's a Braille steel and the 16 years an oddly enough is related to the shape of the rail yes it's the shape of the rail so if if you have a certain shape of the rail a 1 meter of that Rail will have a certain weight yes so 6 means that the mass of 1 leader of the rail of that product is a 6 but that's 1 way to do things so why is it so important well obviously you have different types of rails yes to you it may look like they're all the same but they're very different so nowadays with the conferences in Europe when you develop a very large the distances of high-speed trains you have to make sure that the trades can go from 1 track to the other track in other countries like this it's important that you know they all have the same shape and all the same type of materials so there are European I specifications for rails against and the 13 674 here and some them examples are 200 hour to 20 . 2 6 etc. They and number it is related to the hardness Of the material hardest according to the Britnell hardness and out why why is the hottest important in the case of rails will because of the friction and wear it that's the reason this but of course when when you have these numbers but there are according to the the specifications strengths requirements In typical requirements are reviewing 1300 made plastic and certain composition requirements such as low enough phosphorus content so you don't have unbridled again and with which rails you have the rails and useful cranes as well so the use for light transport for trams for subways spot they all have their own specifications end of rails continuously replaced Nesta they wear out you can't it's big business that's because once you have a Railway it means that you know every so often the rules need to be replaced Whitney walks
another example please let me know In the the the offer In the last long the coordination the more this is the standard line of making these connecting on nowadays we actually use the right on that 1 the make use is of that all the the country so if you look carefully at this time last year was involved and you know at the start this year was like its structure and destructive on the it was it was this 2 mountains around your friendship that we need to open it the way inspired work in many notches you making of fracture not in right here and 2 parts burst into sports but perfectly you don't have anything this is what to we have here the only way I think that what look the them I think some of this is not the sensible according to the and then you can see in the software it is also because the ones we have something "quotation mark parliament along work so often that it feels elements such as sulfur is very fast and we know that many people in the we have a lot of the yield on the machine this is a great example where
actually use the rental market to of the the "quotation mark there is this is the smallest overview of this family there was a lot of steel the knowledge have quality this year of 1 February of the this year or early next month at the moment so as tendency sincerely wildly we don't think of the and University "quotation mark it was hot and the world Morley and get companies having standard the equivalent I think this is the end of what I think that what we do and the construction the the streets In the last 2 years part of the world what we and want to the corresponding because you have to do something for me and this is and that is that you want to you standards the 1st day there and European countries have worked however the use of violence on the other side of the government and the states all of their own it's been a lot of successful everything thing I have heard that the and there way to passing by was you in this way the specifications of the base of signal code which is related to the application and the number of people which it will cost the city so much in the interest of the capital on "quotation mark the medical industry last year so as it's not in the long history each have the the pressure In late last year specifically the and there is no other way to the race is still ranks in Europe and that is a highly placed on composition the be mainland that was in the form of a group the investment agencies allow the amenities of less than 1 way do that it was the the b I want
it's this part police said many the contents of the year
and of of to make money not in the center of what want but less than 5 per cent in the office of the next means the last time I was 1 of the other on the and it has been on the that is watching the move and was always will the combination of all of them only here the is time yes we find that the or was if you get this but there is still water according to the specifications it means that it is not going to be provided by the Ministry of the Justice right in my heart here are we going to do toughness that made the statement you will have to be in the the case ,comma specifications as measured by the knowledge that the fact that they are also and then must these materials as long as there are quite a bit in the name of the product there requirements and what you you the next thing mostly in the office of the world but this year because the year on the Net and on we want to do he the
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