Welding 4130 to 5L X 52 ?

By adrian adams Date 06-19-2007 12:17

I have been tasked with running a weld procedure to qualify the welding of AISI 4130 to API 5LX52. The material will be 5" 3/4 w/t Pipe. Post weld Heat Treatment is not an option, but the good news is mechanical strength will only have to meet the X52 material. Can any one give advise on the welding consumables (tig root and FCAW fill and cap is proposed)and any tips on heat input run size ETC.

By Fredspoppy (**)

Date 06-20-2007 05:43

AA,
Don't think welding consumables are going to be your problem. To match the X52, most of the 70 series consumables will fit the bill. The problem will be the properties on the 4130 side of the weld, especially high HAZ hardness. In most cases, PWHT of 4130 is essential to adequate service life. High preheat/interpass temperature and heat inputs help, but can only do so much. You didn't say what the applicable fabrication Code and final application of the weldment would be. Can you add some info here?

By adrian adams Date 06-20-2007 12:10

Fredspoppy
I will be using ASME 1X for the testing and ASME B31.3 as the process spec.
If I manage to get to the final stages! the process pipe ( used for high pressure cooling mud when drilling) will be 100% radiographed and crack tested, followed by pressure testing at 7,000 psi

So my main concern is to meet the minimum requirements of ASME 1X mechanical tests, (tensile and bends).
What do think my chances are?

By chall

Date 06-20-2007 12:50

For the same materials we have used ER70S-2 and E 7018 successfully. We had to satisfy NACE 0175 for our application. We utilized 450F preheat, PWHT and a temper bead deposit. The resulting PQR passed all the usual mechanical tests, as well as HRC not greater than 22.

From the thickness you listed, I am curious as to why PWHT is not an option. 4130 at 3/4" seems like it should be subject to PWHT in my opinion.

Charles

By adrian adams Date 06-21-2007 11:45

Chall
Thanks for your information

The decision not to PWHT was taken (by others)based on the ASME spec, 3/4" or less (close call I know)PWHT is stated as NONE. Also concern that some of the welding will be in close proximity to valves and of course the big one, cost

By Fredspoppy (**)

Date 06-21-2007 16:21

Gents,
B31.3, Table 331.1.1, says for steels with 1/2% < C <= 2% PWHT is required when over 1/2". 4130, with 0.8-1.1Cr would fall in this category, if covered by B31.3.