Stress Relief After Welding of 1.7734.5 (15CDV6)

[teknomiks]

Hi

Do we need to apply a stress relieving operation after welding of 1.7734.5 (quenched and tempered) tubes ?. Tubes will be subjected to fatigue loading and vibrations in a critical application.

I wonder if heating for stress relieving will reduce the tensile strength of material. What can be the differences of stress relieved parts and non stress relieved parts for longtherm use.

Thanks

 

[metengr]

teknomiks;
Welding of quenched and tempered material must be performed with caution for the reason you mentioned. As a minimum, the stress relief temperature would require to be below the original tempering temperature by at least 20 deg C to avoid changing the bulk mechanical properties of the base material (quenched and tempered).

Beyond this other factors come into play like weld joint type, location and loads in service.

Can you provide more detail as to the function of the component and type of weld joint?

 

[metengr]

teknomiks;
In looking closer at this material, you can probably weld with preheat and selection of an interpass temperature to avoid excessive heat input into the base material. It looks like this low carbon, high strength alloy steel does not require any post weld thermal treatment.

http://www.osbornbujon.com/15CDV6.htm

 

[teknomiks]

Osbourne has also a weld spec on 15cdv6. It says that a fatigue strength reduction of 10-20% can be expected in weld seam.

http://www.osbornbujon.com/welding_spec.htm

metengr

This part is a racing component and constructed from 1.7734.5 tubes of 2 to 4mm wall thickness. Whole part will be exposed to fatigue and vibrational loads during use. We are planing to do tests on whole structure and WPS, PQR tests aswell.

Thanks for answers.