Ultrahigh strength cold rolled steel strip for automobile seat

Abstract

The present invention relates to a cold rolled steel strip for an automobile seat, which comprises the following components in percentage by mass: 0.17 to 0.23 percent of C, below 0.01 percent of P, below 0.01 percent of S, 0.15 to 0.35 percent of Si, 0.60 to 0.90 percent of Mn, 0.15 to 0.35 percent of Mo, 0.40 to 0.65 percent of Cr, 0.40 to 0.70 percent of Ni, and the balance of Fe. The yield strength 6s of the ultrahigh strength cold rolled steel strip is 300 to 400MPa, the tensile strength 6b is 350 to 550MPa, the elongation rate delta is more than or equal to 30 percent, and the hardness is 75 to 85; and the ultrahigh strength cold rolled steel strip has high flanging performance.

Description

Technical field

[0001] The invention relates to an ultra-high-strength cold-rolled steel sheet, in particular to an ultra-high-strength cold-rolled steel strip for car seats. Background technique

[0002] In recent years, affected by the demand for lightweight automobiles, ultra-high-strength cold-rolled steel sheets with a tensile strength of 880-1170 MPa are gradually being used in the framework of car seats. Since the car seat frame is manufactured by a stamping process, the ultra-high-strength cold-rolled steel sheet is required to have excellent flanging performance with a hole expansion rate of 75% or more after punching specified in JFST1001-1996.

[0003] On the other hand, ultra-high-strength cold-rolled steel sheets with a tensile strength of 880 MPa or more are now used as reinforcement materials for shock absorbers and doors. In order to improve its processing performance and welding performance, many researches have been carried out. For example, the Japanese Patent ...

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