Patent ID: 11085098

Abstract:
Disclosed is a Grade 550 MPa high temperature-resistant pipeline steel, the chemical elements, in mass percentage, being: 0.061%≤C≤0.120%, 1.70%≤Mn≤2.20%, 0.15%≤Mo≤0.39%, 0.15%≤Cu≤0.30%, 0.15%≤Ni≤0.50%, 0.035%≤Nb≤0.080%, 0.005%≤V≤0.054%, 0.005%≤Ti≤0.030%, 0.015%≤Al≤0.040%, 0.005%≤Ca≤0.035%, and the balance being Fe and unavoidable impurities. Also disclosed is a manufacturing method of the Grade 550 MPa high temperature-resistant pipeline steel, comprising the steps of: smelting, casting, slab heating, rough rolling, finish rolling, controlled cooling, and air cooling to room temperature. The pipeline steel has an excellent mechanical property under a high temperature.