Manufacture of high tensile steel

Abstract

Abstract PURPOSE: To manufacture high tensile steel excellent in strength, toughness and weldability by rapid cooling low-carbon steel billets of a very few S content, after heating at a low temperature and rolling under a special condition. CONSTITUTION: Steel billets containing 0.005W0.08% C, <0.6% Si, 0,6W2.0% Mn, 0.005W0.08% Al, <0.004% S, and furthermore, if necessary, one kind or more of 0.005W0.05% Nb, 0.01W0.08% V, 0.005W0.08% Ti, 0.1W1% Ni, 0.1W 0.6% Cu, 0.1W0.6% Cr, 0.05W0.2% Mo, 0.0005W0.005% Ca, 0.001W0.03% REM, are heated at a low temperature of 900W1,050°C. In addition to being rolled in the region of recrystallization of austenite grains, the billets are rolled at a reduction rate of ≥60% at ≥850°C and again rolled in the two phase region of (ferrite + austenite) of 20W70% ferrite volumetric rate at a reduction rate of 10W 60%. After being rolled, the billets are rapidly cooled at a quick cooling rate of more than 10°C/sec to ≥600°C temperature in order to manufacture high tensile steel excellent in weldability. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Hiroo Matsuda
• 👤 Hiroshi Tamehiro
• 👤 Mamoru Ohashi

Bibliographic Details