On the High Temperature Strength of Ni-Cr-W Alloys

Abstract

Alloys of Ni-Cr-W-C system were investigated to find a new forgeable alloy which may satisfy the properties required for tube materials of an intermediate heat exchanger for atomic energy steelmaking.
In case of a constant carbon content of around 0.08 weight %, the highest creep rupture strength in air at 1000°C and 1100°C was observed around Ni-20Cr-20W in the Ni-Cr-W system investigated.
Creep rupture strengths at 1000°C and 1100°C of the Ni-20Cr-20W alloy increased with increases of the carbon content and solution heat treating temperature and time.
Details of these phenomena were discussed through the observation of the structures and the analyses of precipitated carbides of materials subjected to the solution heat treatment and the creep rupture test at 1000°C.
The potential of the Ni-20Cr-20W-xC alloys for the required material seem to be very high.