Hi, I'm qualifying a WPS by ASME IX Material: p45-p45 (ASTM B 729) Thickness: SCH 80 Diameter: 6 " position 6G Filler metal: ER320LR wITHOUT BACKing GTAW welding process Gas: Argon 100% No PWHT Mechanical tests are being rejected breaking over the 76 ksi on weldment. The specific base material 80 ksi tensile strength. Rx was applied which evidence no health or lack of fusion welding. 1. Why do you think you could be happening? 2. It is recommended for this alloy some PWHT? 3. Do they have any recommendations for avoiding this is rejected for this reason? Thank you Reynaldo Mejias
P45 include nickel based alloys, ER320 is an austenitic stainless if I remember correctly. ER320 filler metal: 20% Cr, 36% Fe, 34% Ni ASTM B729: 32-38% Ni, 19-21% Cr, balance Fe and at touch of this and a dash of that. Looks like a good metallurgical match.