I did a search on this and not only did I not find what was looking for, the more I looked the more confused I became. ELpolacko mentioned in the broken Mustang II based front suspension thread that he uses 1010 steel for his front suspensions. This is where I got really confused. I called my local supplier and asked about 1010 and was asked about several different versions of 1010........ "Uhhhhhhhhh???????? I don't know" wasn't a very intelligent answer coming from me. Even if most of us don't build our own front suspensions or frames, we all end up using various bits of raw steel and aluminum for various brackets and mounts. I know that I have made mounts out of materials that I had laying around not really knowing anything about their makeup or origin only to have them fail some time later. Not all of this can be blamed on using the wrong material for the job, design factors come into play also but starting with the right material in the first place could sure go a long way toward having a stronger, safer end product. Especially when it comes to things like motor mounts, spring perches, shock mounts, brake caliper brackets, headlight mounts, etc. So what I am hoping for is a nice clear rundown of what materials we should be using in which basic applications and how to intelligently ask for them from our supplier. Thank you in advance for taking the time to help educate us.
Sounds like your "supplier" needs an education, or you need a better supplier.Start here: http://www.arcraftplasma.com/metalstd.htm Your local guy would probably know 1010 as Mild Steel.
You should talk to a mechanical engineer if you REALLY want to know the hows and whys, I majored in ME for a while, and it still confuses me. Surface finish is one of the main factors to be concerned with. That's why shot peened rods are "better". The surface is smoother, and a little harder. more dificult for cracks to develop due to surface irregularities. as for 1010 mild steel, different hardness' are available, cold rolled. http://www.meadmetals.com/coldrolled.htm its a bigger topic than I can cover without my textbooks.
As a real bona-fide metallurgist (at least that is what my degree says...), and the unofficial HAMB metallurgist, what you want to ask for is "cold rolled mild steel". 1010 translates roughly as: the first 10 means plain carbon, no alloying; the second 10 means nominally .10 percent carbon. There are numerous grades of "mild steel" of which 1010 is one grade. Mild steel is just a general term that really means low carbon and little or no alloying elements added. What El Polacko was commenting on is that he has seen A36 steel used. As in ASTM A36 is the specification. A36 is typical structural steel. Such as I-beams, channel, large plate, etc. Techinically A36 is a mild steel, in that it is low carbon. The problem with A36 is that it is not as high of quality and has more impurities and potential defects that are not desireable for parts that are cycled, such as suspension pieces. Now back to your question, ask your steel supplier for "mild steel", that you want "cold rolled", not "hot rolled pickeled and oiled" (HRPO) and not A36, but something "like 1010 or 1018". That will get you good material that you can weld without any troubles, as well as form to some degree without cracking. Any "low alloy" steel, such as 4130, 4140, 4340, or other numerous grades are all small additions of alloying elements. You have heard of "chrome moly"? Well that means chrome and molybdenum are added to the steel, which is what the 41xx series are. The 43xx series are nickel, chrome and moly as alloying. You do not want these as they are going to create more welding problems. Unless you know what you are doing, stick with plain carbon types. Feel free to PM me with any questions specifically. Terry
while I agree that for most applications nothing more than a nice mild steel is needed, there is nothing special to welding 4130 or 4340, all you need is a tig welder. you can use a mig but preheating the steel is recommended. these alloys are heat resistant, very tough and have decent memory. they weigh about 1/3 less than equivelent strength of mild steel. unfortunately I find that the cost of these materials is more of a limiting factor than there workability
"Nothing special" to welding 4130 ? Ask Toby Tobias,the sucessfull Penslvania Modifed racer, about using 4130 for a roll cage.Actually,you can't,he's DEAD. Chrome Moly roll cage broke. Better yet,ask Brad Doty why he's in a Wheelchair. Chrome Moly cage broke,in a wreck at Eldora.Now he is paralized. Ask Doug Wolfgang how he broke his neck the last time. Chrome Moly cage broke. Without the necessary preheat,and correct filler rod, there is the very real risk of brittle welds with Chrome Moly.
I don't know about tobias' wreck but I do know that wolfgang and doty's injurys were sustained in SEVERE crashes. I've actually met and talked to brad doty after the crash. sprint cars and midgets are very dangerous vehicles. Have you ever seen what happens in a wreck where the track allows mild steel tubing? I have, even with the required larger diameter and heavier wall thickness mild steel crushes like aluminum. I've hit the wall head on at 90+ in a chromoly midget frame that was 14 years old. it didn't break one weld out of the front end. Infield safety crew thought I was dead but I walked away with bruises. I had repaired parts of that front end with a mig welder previously. just apply a little heat and be careful. The largest problem I've seen on welds with chromoly is the welder not using enough filler to maintain good penetration. That is the only time I've had a weld fail on a chromoly car. the one thing you cannot do though, is chrome it. this causes hydrogen embrittlement. basically it makes the material brittle and prone to cracking. The car I crashed is the number 4 in the front row.
Just to clarify, the primary reason that shot peening is better is that it leaves residual compressive stresses on the surface, which are beneficial in preventing crackes from initiating. The residual compressive stresses counteract the applied tensile stress and that makes the affect of the applied load to be lower on the metal. A smooth surface finish is also better for crack initiation.
Hydrogen embrittlement (HE) is a phenomenon that causes the steel to fail under a sustained load. You will not see HE affect in a sudden impact or tensile test. To check for HE the procedure is to load the part up to about 90% of yield and hold under that load for 72 hours. If no cracks, then it is considered not embrittled. If it does crack, obviously it was. HE is a factor for steels above Rockwell C 30 (generally). Which means heat treated, or in the case of MIG welded Cr-Mo steels, the weld area is above Rc 30. Actually any process that can have hydrogen, such as acid cleaning, can cause HE; not just plating, although plating is the most common source. HE does not cause the part to be brittle and fail over long period of time. That is fatigue cracking (cyclic loading over long time below yield strength stress level) which is a result of a hard low ductility weld in a region of softer more ductile metal. The crack initiates in the transition area. TIG welding of Cr-Mo does not cause the weld to become hard like MIG, so you do not get the hard-to-soft transition. Known officially as a metallurgical notch, it is not good for fatigue crack resistance.
learn something new every day..... always thought it made it brittle. as far as the mig welding goes, does heating the area help the fatigue cracking or is it just the nature of the mig weld that does this? I've always found even the soft wire for the mig to be rather hard
The heating you do (pre heat and/or post heat) with MIG is very helpful in preventing the weld and small are next to weld from becoming heat treated. The fast cooling causes the area to become untempered martensite (metallurgical terminology), which is very high hardness and brittle. A file is nearly untempered martensite as example. By heating the metal and the subsequent slower cooling you may just be keeping the metal from forming martensite. This is why TIG is needed for Cr-Mo, the weld does not form martensite. By nature of the welding process, MIG welds cool very fast, effectively being quenched like in heat treating, this makes them real hard. The hardness and ductility transition is what contributes to fatigue cracks. Gas welds (oxy acetylene) are very ductile because they cool so slow. That is why hammer welding is ideal with gas welding. You could take a torch and heat up the MIG welds after and "temper" the martensite to make it less hard and more ductile, as a help. But for the best results you really need to get it hotter than the austenitic transition temp (varies for steel grade, but approx 1550-1600 F) and slow cool. This would enable you to avoid martensite at all. Controlled heat treating time and temp, with quench at controlled rates and then tempering is what springs and other heat treated parts use to get a desireable tempered martensite structure. You would have difficulty to control it with a torch in your hand, although you certainly can make the welds less hard by a post heating. BTW, glad you walked away from that crash, the safety structure did it's job.
I recommend you go read Carrol Smiths "Screw to Win" oops real name: Engineer to Win and Nuts bolts and fasteners and plumbing handbook http://www.amazon.com/gp/product/08...=pd_bbs_3/104-7480064-2291946?ie=UTF8&s=books http://www.amazon.com/gp/product/08...=pd_bbs_1/104-7480064-2291946?ie=UTF8&s=books The man has forgotten more about fabricating than most will ever know
Those are some damn fine metallurgy answers. Reminds me of all the things I've forgotten since graduating (BSMet '94) - still have the books, but haven't use 'em in years. Now if you want to talk tungsten carbide, I'm your man!
Shit, I graduated in 87 (BSMetEng also) and I don't even do "real" metallurgy anymore! This is as close as I get now. Kinda fun to help spread the knowledge to help people out and prevent problems.
I once rebuilt a super gas drag car with an Alston chassis. The original builder mig welded the entire thing with a 110 volt mig, which done correctly wouldn't be so bad, but he fabbed the steering column out of chrome moly. It had a quick release hub that required welding, which was of course done with the same mig welder in the same inexperienced hands. I had some questions about something on this car sometime after he sold it and I had it in the shop for some repairs, and during our conversation, he was laughing about the steering column and how he had to weld it 7 times before it finally stuck together. He still used it, and was running in the 160-170 mph range. Some people have no fear!
Yes, thank you everyone. I know that this is a huge subject and I really appreciate everyones insight. My local supplier knew what 1010 was, it's just that he asked me questions about it that I couldn't answer and that made me feel stupid. I have read Carrol Smith's Nut, Bolts, Fasteners and Plumbing Handbook. If anyone reading this has not read it and is the least bit interested in know more about the bolts that you use, READ THIS BOOK. I did not realize that Engineer to Win was available. I will definately be purchasing it ASAP. In the mean time, just to be clear, I can go into the steel supplier and just ask for "1010 or 1018 Cold Rolled" and be fairly certain that I am getting a mild steel that is quality enough for fabricating brackets and doo-dads without fear of failure do to the quality of the steel (obviously provided that the design and usage is correct)? What are the physical property differences of 1010 and 1018? Judging from what has been said, 1018 would stronger or more resistant to bending? Is this correct? Given the choice, what would be the determining factors in deciding which to use? Again, judging by what has been said, 1010 would be better in a situation where the steel would need to be formed? Is there ample differences between the two that would make a person choose one over the other. Sorry for all of the questions, I'm just trying to be ultra clear about this. As far as "chrome moly" is concerned, I knew about the hardness of MIG welds as it relates to 4130, etc., but what about "normalizing" after TIG welding? I have heard that it is darn near impossible to normalize correctly using a simple open flame and that more harm than good is done using this technique. Is this true? Is it necessary to normalize a Tig welded joint on "chrome moly"? Anyone care to delve into the proper usage of aluminum? If I were to pose the question, "Say a person wants to replace a 3/8" thick mild steel bracket that is placed in shear(not sure if this is the proper usage of terminology) with a bracket made of aluminum. How would he know what type of aluminum to use and how much thicker than steel it would need to be?". Is that a reasonable question to ask or are there just too many factors involved for the question to be answered? Thanks again!
Been at the Asphalt Inv show all day, here are some responses to your questions. In general, higher carbon content gives higher strength, assuming all else being equal (heat treat condition, cold work amount, etc,). The last two digits of the 10xx, is the carbon content in 0.xx percent, so 1018 is nominally .18 percent C. Of course there is tolerance and it varies from about .15-.21 while still meeting the requirement. The first two numbers are the alloy identifiers. For what you are doing, either 1010 or 1018 will work. You are going to be buying normalized condition most likely, which is low strength and no cold work. Good for forming. As long as you keep the C content below .35 you can weld without any real concerns for the chemistry. You still have to weld with proper good penetration welds. Higher than .35 Cn will require pre-heat and more controls that you don;t want to mess with. Most all mild steel is less than .35 C. There is reason that safety requirements dictate TIG welds for Cr-Mo, because it is needed for good strength welds. As I stated previously, using a torch to go over MIG welded Cr-Mo is sketchy at best, although it will help. Cr-Mo is much hogher cost, stick with mild steel. Aluminum is a whole different set of concerns. It can be as strong as steel, especially low strength mild steel for example. But alum can not be welded except for certain alloys, not all are able to heat treat, and it has corrosion issues. So for alum it really depends on what you have before a judgement can be made.
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