Weld Hardness / NACE MR0103 & MR0175

[Erick21]

Hello,

NACE MR 0175 states that hardness must be check on the PQR for carbon steel welding and should not exceed 22 HRC without PWHT. NACE MR 0103 states both value 22 HRC and 200HB and refers also to NACE RP 472 wich not define clearly a precise value.

How to be sure on which value we have to base the hardness test?

thanks

 

[SJones]

By picking one standard and sticking to it. Please note that MR0175 only allows HRC for welds if the design stress is less than two thirds SMYS AND PWHT is applied.

MR0175 is for upstream oil and gas whilst MR0103 is for refineries. There should be no need to mix them up.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04