Disclosed is a high-strength welded steel pipe for airbag inflators that has high toughness and workability. A base material portion of the steel pipe has a composition containing, in mass %, C: 0.02 to 0.08%, Si: 0.001 to 1.0%, Mn: 0.1 to 2.0%, P: 0.1% or less, Al: 0.01 to 0.1%, N: 0.01% or less, Ti: 0.01 to 0.20%, and V: 0.01 to 0.50%, with the balance being Fe and incidental impurities. The base material portion has a structure that includes a ferrite phase having an average grain size of 10 μm or less at an area fraction of 90% or more and a Ti, V-based carbide having an average grain size of 10 nm or less and dispersed in the ferrite phase. The welded steel pipe has a high tensile strength TS of 780 MPa or more and a strength-elongation balance TS×El of 15,000 MPa % or more. The difference ΔHV in Vickers hardness between the base material portion and the welded portion is 60 points or less. In a softened portion having Vickers hardness different from the Vickers hardness of the base material portion by at least 30 points, a softened width Ws in a circumferential direction is 0.05 mm or less.
High-strength welded steel pipe for airbag inflator and method for manufacturing the same
28.05.2019
Patent
Elektronische Ressource
Englisch
IPC: | C22C Legierungen , ALLOYS / B21C MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING , Herstellen von Blechen, Metalldraht, -stangen, -rohren Metallprofilen oder Halbzeugen auf andere Weise als durch Walzen / B60R Fahrzeuge, Fahrzeugausstattung oder Fahrzeugteile, soweit nicht anderweitig vorgesehen , VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR / F16L PIPES , Rohre / C21D Veränderung der physikalischen Struktur von Eisenmetallen , MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS / B21B Walzen von Metall , ROLLING OF METAL / B23K Löten , SOLDERING OR UNSOLDERING |
HIGH-STRENGTH WELDED STEEL PIPE FOR AIRBAG INFLATOR, AND METHOD FOR MANUFACTURING SAME
Europäisches Patentamt | 2016
|Europäisches Patentamt | 2018
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