Properties of P91 Steel Steam Conduit Pipe with Low Hardness in a 600 MW Power Plant

Abstract

The hardness of P91 for HP loop pipes was lower than required in standard in a power plant which has run for about 35,000 hours. The experiments about Metallographic and conventional mechanical properties were done in this paper. The results show that the metallographic of P91 with low hardness was abnormal, creep damage was not found, and mechanical properties were poor.So the HP loop pipe with low hardness cant continue to be used safely.After re-heat treatment for HP loop pipe with low hardness,the results about metallographic and mechanical tests show that the performance of the pipe is good,and can continue to be used.