MANUFACTURE OF UNNORMALIZED HIGH TENSION STEEL PLATE

摘要

PURPOSE:To improve remarkably the strength of a steel plate without deteriorating the toughness by carrying out slight rolling in a specified temp. range when the temp. of the steel plate is lowered after finishing rolling in the austenite range or the austenite-ferrite two-phase range. CONSTITUTION:The temp. of a steel plate is lowered by allowing the plate to cool, cooling it with water, or applying other means after finishing rolling in the austenite range of 950-650 deg.C or the austenite-ferrite two-phase range. When the temp. is lowered to the temp. range of 650-300 deg.C, slight rolling is carried out at >=1% draft in the temp. range, and said cooling is continued. It is preferable to produce >=1% strain in the surface of the plate with a leveler after the slight rolling.