Chromoly welding compatible steels

Date 05-08-2003 13:59

Roughly saying all kind of steels can be welded to each other. Your question is too general to answer it in detail. Witch kind of steel do you want to weld to Cr-Mo steel?

By Lawrence (*****)

Date 05-08-2003 14:51

An anarchist looking for dogmatic instructions... How deliciously ironic!

The ASM material guide Vol. 6 (possibly available at your local public or college library) is an excellent source for the type of cross-matching data your after :)

By anarchistw Date 05-08-2003 21:41

sorry, I probably should have just stated my question this way. I want to replace some tubes on the rear frame of my 1994 harley sportster with different ones I will fabricate. I have heard from a relativly knowledgable friend that the frame is constructed with some type of chromo. I would like not to have to use chromoly steel because of how difficult it is to work with. So basicly I am asking, is there a type of steel that will work best for welding to the exhisting frame and still be somewhat easy to work with.

By George-kh (**)

Date 05-09-2003 11:50

Cr-Mo steels, depending to Cr and Mo content in steel, are creep resistant up to 600C.
Quality steels are creep resistant too; however up to 300C maximum.
According to DIN EN 17175 (seamless tubes) you can use following steels but remember they are quality steels.
St 35.8, St 45.8, 17Mn4, 19Mn5

By GRoberts (***)

Date 05-09-2003 19:20

In order to avoid some confusion, I think there are two types of Cr-Mo steels being talked about here.

The tubing being mentioned is most likely a high strength type of Cr-Mo steel, 4130 for example, with about 1% Cr, and .2% Mo. I'm not sure about tubing, but I know in thicker sections it is water or oil quenched and tempered to obtain a high hardness with adequate tougness. It is often used as high strength tube, machine tools, oil field, etc. There have been several discussions on welding this type of material if you search the archives.

The other kind of Cr-Mo steels are designed to have high temperature strength and resist creep, as already pointed out. These steels start out at the low temperature end with only 1/2 Mo, and continue though to martensitic stainless steel. Some popular grades contain 1 1/4 Cr, 1/2 Mo, like 80XX-B2, or 2 1/4 Cr, 1Mo, like 90XX-B3, or 5Cr, 1/2 Mo, like 80XX-B6, or 9Cr, 1Mo and V like 90XX-B9. They are normalized and tempered in order to achieve their high temperature properties.

By aircraft (**)

Date 05-09-2003 11:57

I have never ran into a OEM Harley frame that was made with chromoly, not that there not one, but I do a lot of bike frames.
However I always use chromoly for any replacement tubes or a frames from the ground up.

By 49DegreesNorth (**)

Date 05-09-2003 18:29

What's so bad about working with Cro-Mo? Just curious...

By George-kh (**)

Date 05-12-2003 07:16

Assuming filler metal is chosen correct, these steels are susceptible to hardening and under bead cracking. preheating and post weld heat treatment (PWHT) shall be done correctly to prevent cracking.