welding P5 material (5 Cr .5 Mo)

[wczimm22]

we have a customer requesting hardness testing of the welds. we have a rebound tester but, the material types we are able to select from are limited to stainless steel, steel, cold worked tool steel, aluminum and copper based material. chrome-moly (P5) is a nickel based material. I am not sure which material selection I should use with the rebound tester.
Any ideas or info would be greatly appreciated

 

[metengr]

P-No 5 is not a nickel based material, it is a 5% Cr-0.5% Mo low alloy steel. A rebound hardness tester can be used if calibrated on steel. It sounds like you are unfamiliar with hardness testing and should have this done by an outside testing group or lab.

 

[weldstan]

Work done by ARAMCO and others have shown considerably lower values with rebound than when tested by Brinnel, Sonadur and Vickers instruments.

 

[Oskarin2012]

Weldstan is right. In fact, Shell Group does not allow the use of rebound testers because of deviations in values (importantly lower) against Vickers, Brinnel or Knoop instruments. If you look at the Welding DEP´s you´ll find this prohibition.

Hope it was helpful.

Cheers

 

[weldstan]

The companies for which I have worked and directed contract requirements for the past 40+ years,
rebound testing has been prohibited for critical welds in petrochemical services for exactly those reasons.