| 摘要 |
PROBLEM TO BE SOLVED: To produce a 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. SOLUTION: A steel, having 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, is used. After tube making, the resultant steel tube is hardened at 850-1000 deg.C and, cold-worked to prescribed size and used in this as-cold-worked state, or, after cold working annealing treatment is applied. By this method, the steel tube, which has high strength, high toughness, and high dimensional accuracy, enough to be used as an accumulator for an air bag, and also has excellent workability and weldability, can be obtained. |
