welding different materials

[larryli2004]

Hi,

Is there any problem to weld API 5000 4130 low alloy steel with A333 Gr. 6 pipe? Does anyone see any welding issue here? I appreciate your advice.

Thanks.

 

[larryli2004]

Sorry, I mean weld API 5000 4130 low alloy steel weld neck flange with A333 Gr. 6 pipe.

 

[stanweld]

Please do not cross post; re your ? on "Pipelines, Piping..."

 

[MikeMet]

There is always the possibility of problems when welding AISI 4130 material due to the formation of hard heat affected zone which is susceptible to hydrogen cracking. I would recommend a generous preheat and a post weld stress relief. You can use a 70ksi strength filler metal. I also recommend your coupon for weld procedure qualification have one piece with a bevel and the other a flat face that way you can get the notch in the HAZ so crack propagation is completely in the HAZ. This is the most conservative way to qualify the weld procedure.

 

[Salll]

A preheat of 200 degrees C and a post heat of 600 to no more than 800 degrees C and allow to cool slowly in air. If cooled to quickly, hard and brittle martensite can form in the crystalline structure. Some consideration needs to be given to the application you will be using the weldment in. I am assuming a low temp service application.

 

[Guest102023]

Salll, sloppy terminology there.

1) Preheat and interpass 200°C min.
2) Soak for 2 hr min. @ 200-250°C.
3) Straight to PWHT @1250 for 1 hour. Cooling to room temp. is acceptable.