PURPOSE: To manufacture the titled alloy undergoing no deterioration in the corrosion resistance due to a heat treatment such as annealing and welding by hot rolling an Ni-Cr alloy with low C content under specified conditions and by annealing and cooling it.
CONSTITUTION: An alloy consists of ≤0.05% C, ≤1.0% Si, ≤1.0% Mn, ≤0.03% P, ≤0.005% S, 50W80% Ni, 15W35% Cr, 0.01W0.5% Al, ≤0.0020% B as an impurity and the balance essentially Fe or further contg. ≤0.5% Ti is heated to 1,050W1,250°C and hot rolled at ≥50% total draft and 700W950°C finishing temp. At this time, the draft in the temp. range of ≤950°C is adjusted to ≥15%. The hot rolled alloy is annealed at 850W980°C for 15minW2hr in accordance with the C content, and it is cooled at ≥30°C/min cooling rate.
YOSHIKAWA KUNIHIKO
NAGANO HIROO
MINAMI TAKAO
MIURA MINORU
