A335P91/A335P22,A335P91/12Cr1MoV welding

Date 09-01-2004 05:21

General rule for dissimilar materials in carbon and alloy steels :

1. Strength and alloy content of the filler should just overmatch the lower strength material, in this case P22 and 12Cr1MoV.

2. Weld preheat, post heat and PWHT temperature should be as per the requirement of the higher alloyed material, in this case P91.

Hope you got your answer.

By MBSims

Date 09-01-2004 06:18

For joining P91 to P22, the P22 electrode would be used (ER90S-B3, E9018-B3). But why would the 12Cr electrode be used for joining 9Cr to 12Cr? The lower alloy (ER90S-B9, E9018-B9) would minimize the tendency for carbon migration at elevated temperatures (such as 1000 deg. F and over).

By ajoy

Date 09-01-2004 07:12

please check the composition of 12Cr1MoV.

I thought it is not a 12Cr. type material. Generally in DIN the first digit tells us the carbon percentage /100.

I may be wrong here in interpreting the composition. But in any case the general rule will apply. if this material is really 12Cr type, then 9Cr consumables should be used.

By dragon

Date 09-01-2004 09:19

12Cr1MoV Element:0.05-0.15%c,0.4-0.7%Mn,0.90-1.2%Cr,0.25-0.35%Mo,0.15-0.30%V;
it's Chinese standard.

By MBSims

Date 09-02-2004 00:18

Well, I've learned something new again today! The convention here in the U.S. for CrMo steels is the nominal wt.% followed by the element, such as 2.25Cr1Mo is a 2.25% Cr content and 1% Mo content CrMo steel. When I saw the question and the reference to ASTM A335 P91 and P22, which are U.S. standards, I (wrongly) assumed this was a 12% Cr steel. Thanks for enlightening me on the DIN designations.