HEAT RESISTANT STEEL FOR MAIN STEAM PIPE

摘要

PURPOSE:To obtain a heat resistant steel usable as the material of a steam pipe for a thermoelectric power plant, having superior strength at high temp., and causing hardly embrittlement during use by adding V, Nb, W and other elements to a heat resistant Cr-Mo steel. CONSTITUTION:A main steam pipe used in a thermoelectric power plant is made of a heat resistant steel contg. 0.05-0.15% C, 0.3% Si, 1.5% Mn, 1.0% Ni, 8-11% Cr, 0.75-1.5% Mo, 0.1-0.5% W, 0.1-0.3% V, 0.02-0.20% Nb and 0.02- 0.10% N. The heat resistant steel has =12.2kgf/mm.2 creep rupture strength after holding use. The steel has superior strength at high temp., satisfactory embrittlement characteristics, high hot workability and weldability.