8630 chromoly? school me please

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been lurking around here for a while and finally have a question.  I'm narrowing an axle housing and the inner Cs are kinda ratty looking, so I thought I'd flip the coin for some namebrand junk.  The axle tubes are 1/2" thick, I'm assuming DOM.  The Cs are 8630 chromolly and look plenty thick, I'll be TIG welding them inside and out,so I'm not lacking in material or weld area.  I've searched but just came up with the regular rollcage threads talking about 4130.  so does ER-70s-2 fit the bill? preheat? post heat? crank it up and burn'em in?  any help is appreciated,Dan
Reply:Originally Posted by daniel04...the inner Cs are kinda ratty looking, so I thought I'd flip the coin for some namebrand junk.  Dan
Reply:As far as I know, 8630, is usually used in cold forgings. I believe it is what companies like Snap-on make their sockets and wrenches with.8630 has the same carbon content as 4130..hence the "xx30". They are both "low carbon" steels.The 8630 has .5% chromium where 4130 has a full 1%.Both alloys are close on the molybdenum content at .20% and .25%...but the 8630 has nickel that the 4130 doesn't, .5%.Since it has the same carbon content and a trace amount of nickel it should weld without an issue with ER70S-2 or ER80-D2 with no pre/post heating required. Although, the thickness of the materials will take some good weld prep and possibly multiple passes...but that's just my opinion.- Paulhttp://all-a-cart.comWelding Cart Kits and accessories
Reply:8630 is AISI# 8630 and ASE# is 8630.  the chemestry is .40-.70 NI, .40-.60 CR and .15-.25 mo.  Considered CRNIMO steel and most closley matches ER80S-2, 70S-2 would not do you as good a job, because of the chemestry and the tensil.  Can be reserched in all AWS books.  John
Reply:sorry, my typing is not that good.  ER80S-B2   sorry  John