EFFECT OF AGING ON THE MICROSTRUCTURE AND TENSILE PROPERTIES OF AN ALLOY 800 9CR-1MO STEEL JOINT

The effect of aging on the interfacial microstructure and tensile prop erties of as-welded and post-weld heat treated alloy 800/9Cr-1Mo steel joint (welded with Inconel 182) was investigated. These joints were p ost-weld heat treated for 1 h at three different temperatures, viz. 97 3, 998 and 1023 K, and then aged at 845 K for 100, 500, 1000 and 5000 h for accelerated simulation of long-term elevated temperature service exposure. It was observed from this investigation that aging at 845 K up to 5000 h had only a marginal effect on the tensile properties of the alloy 800/9Cr-1Mo steel joint, with the Inconel 182 weld/9Cr-1Mo s teel interface and the 9Cr-1Mo steel HAZ exhibiting excellent resistan ce to aging induced microstructural instability.