5% Ni Steel???

[90harley]

Dose anyone know about 5% Nickel Steel used in the construction of LNG vessels? I'm working for Reliance in India on a set of Coke drums and the customer asked if we had experiences welding 5% Nickel Steel. One of their tankers caring LPG has experiences cracking and they are looking for us to repair it. The chose for electrode by the plant would be ERNiCrMo-3, an electrode we use quite often however I know my welders are not certified to weld this Steel. I have found several pieces of literature regarding the use of the Steel however I cant find a UNS or ASTM number for 5%Ni. Thanks for any information.

 

[metengr]

Look here

http://www-off-axis.fnal.gov/flare/technical_papers/welding_tanks.pdf

 

[REGRUMBLE]

The only one that I see in the tables is type 202 which is UNS20200. There may be others???

 

[metengr]

Look at SA 645 Standard Specification for
Pressure Vessel Plates, Five Percent Nickel Alloy Steel,
Specially Heat Treated

UNS K41583

 

[90harley]

Thank you for the help!!

 

[90harley]

Now that i have found the requirements for the steel I am unsure of my welder qualifications. Under the previsions listed in QW-423.1. if I have a welder that tested on P1 and is qualified up to P11 is he also certified to weld a P11A Group 2 or will I need to test him on this material?

 

[metengr]

Yes, your welders are qualified to weld all P-No 11 base materials based on ASME Section IX. When it comes to Groups, this applies to WPS qualification regarding impact tests.