Welding of AISI 4130 1

[metboss]

Hi all,

I need some advice on weld compatibility of material grade AISI 4130 (7K yield strength) with existing tubing grade J 55 (API 5CT, yield strength 55K).

Are these two materials grades (AISI 4130 and J55) fall under “low alloy steel category” ? Can they be welded together ? if so, what is common filler metals used for the welding and applicable code (ASME IX or any) ?
What are precautions to be taken when welding (pre-heat, PWHT etc.)?

Regards

 

[metengr]

The 4130 is low alloy steel while the J55 is Group 1 material, carbon steel tubing. Yes, they can be joined by welding. Is this a butt weld?

I would suggest an 80 series filler metal if using SMAW or similar with other welding process with 400 deg F preheat. The PWHT temperature and time will depend on thickness of the 4130, and final tempering temperature of the 4130 steel to avoid over tempering.

 

[metboss]

Thanks metengr

yes, it is butt weld.

Can "AISI 4130 and J-5" be categorized as carbon & low alloy steel ??

Regards

 

[metengr]

J-5 or J55?

 

[metboss]

Sorry typo error,

It is J55- (API 5CT).

Are these materials (AISI 4130, J55, K55) low alloy steel ?

 

[metengr]

J-55 is carbon steel, 4130 is alloy steel.

 

[Tmoose]

Is the 4130 Condition N (normalized) ?
I'm guessing the 7ksi yield strength was really 70 ksi.

Motorsports often uses 4130 Condition N. The thin wall sections mean even with modest preheat the cooling is not quick enough to "Quench" and harden the material, especially if mild steel filler is used so the weld proper is diluted.
Even with the relatively intense heat of TIG welding.

http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/chrome-moly-detail.aspx

Is your application bound by industrial codes?

 

[metboss]

Thanks all for your valuable advice.

I have one more query.

There is one more Casing Swage (API 5L X-56) to be welded on to Casing head spool (AISI 4130).

Again, my question is on welding compatibility :

Can we weld API 5L X-56 to AISI 4130 ?

Regards

 

[metboss]

Still waiting for answer to my query.

Regards

 

[metengr]

Yes, you can weld them.

 

[blacksmith37]

API intends X-56 to be weldable; and J55 not to be welded (chemistry is fairly loose). AISI 4130 is not weldable in a refinery but is weldable in oil production . 4130 will need pwht and may need a high preheat--- depending on thickness ,and if you are going to do NDE for cracks.

 

[redpicker]

J-55 is carbon steel, 4130 is alloy steel.

Not necessarily. As blacksmith37 points out, 5L line pipe is intended to be welded, so there are limitations on alloy content. 5CT casing (J55) is not intended to be welded, so the chemical composition requirements are much looser (less than 0.030 P & S and you are good). I know I have seen J55 as 4130, and perhaps even 4140 (I forget if it actually made J-55 or not--in the late '80s early '90s there was a lot of tubing on the market and if someone had some P110 that he couldn't sell, he would often heat treat it to a lower grade just to move it).

My point is that if you are going to weld a casing grade, always get a MTR with a chemical analysis. If you have lost heat traceability, get a chemical analysis done. And, if you are going to weld 4130, watch out for cracks. In thin sections, you can be fine with no preheat/postheat, but if you start getting much over 1/4", it can crack.