Patent ID: 7727463

Claim:
A steel pipe for an airbag system having a steel composition which consists essentially, in mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, at least one of Ti and Mn in amounts satisfying the following equations (1) and (2), Mo: 0-1.0%, Ni: 0-1.5%, V: 0-0.2%, B: 0-0.005%, Cu: 0-0.5%, Nb: 0-0.1%, Ca: 0-0.01%, Mg: 0-0.01%, REM: 0-0.01%, and a remainder of Fe and impurities, Ti≦0.02% (1) 0.4%≦Mn+40Ti≦1.2% (2) wherein the symbols for elements in the above equation indicate the mass % of the elements, the steel pipe having a tensile strength of at least 1000 MPa, and a low temperature toughness vTrs 100 being equal to or lower than −40° C.