Tubes for Hybrid airbag
01.11.2017 | Initiative Automotive
In case of car collision, safety airbag are filled with a gas in a few milliseconds in order to save passenger life. Two main technologies are used to generate gas:
- Pyrotechnic technology : the gas come from the combustion of an explosive
- Hybrid technology : the gas, stored at a high pressure level in a vessel, is released through a nozzle opened by an explosion
Hybrid airbags are mainly used as side, curtain or knee airbag.
If drawn tubes are less and less used for pyrotechnic technology for the benefit of other technologies like deep drawing or stamping, seamless drawn tubes are mandatory for hybrid pressure vessel including a lot of specific requirements like :
- Low carbon content to satisfy US regulation (DOT)
- High mechanical characteristics for burst safety factor
- Outstanding toughness properties with very low transition temperatures for operating temperatures as low as -40°C or -60°C
Such characteristics are reachable using an isotropic metallurgical microstructure. In the case of low carbon steel grade, the best way is a tempered martensite microstructure obtained through a quenching and tempering process.
SMP invested in Saint-Florentin plant into an induction Q+T line in order to offer quenched and tempered solution on tube dedicated to airbag solution but opened also to any other kind of product.