| 摘要 |
<p>A steel tube for an airbag which has a low alloy cost and a strength of at least 1000 MPa and vTrs100 of -80° C or below and a process for its manufacture which can minimize the number of times that softening annealing treatment is performed in a cold drawing step are provided. Stable properties are obtained even when quench hardening is carried out by high frequency induction heating on a large scale. The steel tube has a steel composition which comprises, in mass percent, C: 0.05 - 0.20%, Si: 0.10 - 0.50%, Mn: 0.10 - 1.00%, P: at most 0.025%, S: at most 0.005%, Al: 0.005 - 0.10%, Ca: 0.0005 - 0.0050%, Nb: 0.005 - 0.050%, Ti: 0.005 - 0.050%, Cu: 0.01 - 0.50%, Ni: 0.01 - 0.50%, Cr: 0.01 - 0.50%, B: 0.0005 - 0.0050%, N: 0.002 - 0.010%, and a remainder of Fe and unavoidable impurities.</p> |
