| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel tube having a high dimensional accuracy, excellent in workability, and suitable for parts for an air bag, requiring high strength and high toughness, and its production. SOLUTION: The steel tube for an air bag, with a high strength and high toughness, has a composition consisting of 0.05-0.15% C, <=0.50% Si, 0.30-2.00% Mn, <=0.020% P, <=0.020% S, <=0.10% Al, and the balance Fe with inevitable impurities. This steel tube has high dimensional accuracy and excellent workability and weldability and can secure high strength and high toughness. Further, after tubemaking of this steel, the resultant steel tube is cold-worked into prescribed size and used in this as-cold-worked state, or the steel tube is subjected, after cold working, to annealing, normalizing, or quench-and-temper treatment, by which the steel tube having high dimensional accuracy, excellent in workability and weldability, and suitable for parts for an air bag, requiring high strength and high toughness, can be produced. |
