| 摘要 |
<p>Provided is a steel pipe for air bags which is reduced in alloy cost and has a tensile strength of 1,000 MPa or higher and a vTrs100 of -80ºC or less. A process for producing the steel pipe is also provided in which the number of softening/annealing treatments in the cold drawing step can be minimized. Stable properties can be obtained even through quench hardening conducted by mass-scale high-frequency heating. The steel pipe has a steel composition which contains, in terms of mass%, 0.05-0.20% C, 0.10-0.50% Si, 0.10-1.00% Mn, up to 0.025% P, up to 0.005% S, 0.005-0.10% Al, 0.0005-0.0050% Ca, 0.005-0.050% Nb, 0.005-0.050% Ti, 0.01-0.50% Cu, 0.01-0.50% Ni, 0.01-0.50% Cr, 0.0005-0.0050% B, and 0.002-0.010% N, with the remainder comprising Fe and incidental impurities.</p> |
