HIGH STRENGTH STEEL TUBE FOR AIR BAG AND METHOD FOR PRODUCTION THEREOF

In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1 %, Nb: at most 0.1 %, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01 %, Mg: at most 0.01 %, and REM (rare earth elements): at most 0.01 %, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.