Seamless steel tube for an airbag accumulator and process for its manufacture
US8496763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2009 |
| Grant date | Jul 30, 2013 |
| Priority date | — |
| Expiry date | Jan 22, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/22
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A seamless steel tube for an airbag accumulator which can be manufactured by heat treatment of normalizing without quenching and tempering and which has a tensile strength of at least 850 MPa and resistance to bursting at −20° C. has a stee; composition comprising, in mass %, C: 0.08-0.20%, Si: 0.1-1.0%, Mn: 0.6-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Mo: 0.05-1.0%, Al: 0.002-0.10%, at least one of Ca: 0.0003-0.01%, Mg: 0.0003-0.01%, and REM (rare earth metals): 0.0003-0.01%, at least one of Ti: 0.002-0.1% and Nb: 0.002-0.1%, with Ceq which is defined by the following Equation (1) being in the range of 0.45-0.63, with the metallurgical structure being a mixed structure of ferrite+bainite:Ceq=C+Si/24+Mn/6+(Cr+Mo)/5+(Ni+Cu)/15 (1)wherein the symbol for each element in Equation (1) indicates the number expressing the mass percent of the element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.