STRUCTURAL STEEL HAVING EXCELLENT BRITTLE CRACK PROPAGATION STOPPING CHARACTERISTIC AND FATIGUE CRACK PROPAGATION CHARACTERISTIC AFTER PLASTIC DEFORMATION AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a structural steel having excellent brittle crack propagation stopping characteristic and fatigue crack propagation characteristic even after receiving plastic deformation.;SOLUTION: A steel base material after heated is hot rolled under a condition, which is controlled to that the accumulation draft in a temperature range of 1000-900°C is ≥15%, and the accumulation draft in a temperature range of 900-725°C is ≥75%, and the rolling termination temperature is 850-725°C, and is cooled down to 400°C at 5°C/s cooling rate to form an aggregative texture, in which the X-ray intensity ratio in (211) plane of the rolled surface is ≥1.5 and is larger than the X-ray intensity ratio in (100) plane.;COPYRIGHT: (C)2002,JPO