Steel with yield ratio of 0.9 or more used for ultra-fine grain slideway and production method thereof

Abstract

The invention relates to a steel with the yield ratio of 0.9 or more used for an ultra-fine grain slideway and a production method thereof. The steel mainly comprises the following components in percentage by weight: 0.03-0.07% of C, less than or equal to 0.03% of Si, 0.50-0.80% of Mn, 0.02-0.07% of Al, less than or equal to 0.03% of P, less than or equal to 0.015% of S, 0.02-0.07% of Nb, less than or equal to 0.06% of Mo and the balance of Fe and impurities. The production steps comprise hot metal desulphurization, converter smelting, ladle argon blowing, continuous casting, casting blank heating, hot rolling, reeling, ordinary scouring, cold rolling, continuous annealing, and leveling for stand-by. The defects that the existing same-level high-strength steel is low in yield and the specification and the welding of hot rolling materials are difficult to meet are overcome. The yield ratio of the steel disclosed by the invention achieves 0.9 or more, the grain size of the steel achieves 13 or more, and a steel plate has high yield ratio, appropriate elongation and good spot welding property.

Description

technical field [0001] The invention relates to a steel material and a production method thereof, belonging to a steel for an ultra-fine-grain slideway and a production method thereof, and is more precisely suitable for use in automobile seat slides with a yield strength above 700 MPa and a yield ratio ≥ 0.9. Ultra-fine-grained cold-rolled steel for track or slide rail and its production method. Background technique [0002] The cold-rolled steel used in the car seat slideway or slide rail requires high yield strength, certain formability and good weldability. While the solid solution strengthened steel ensures high strength, its carbon equivalent is significantly increased, and the weldability is difficult. fulfil requirements. At present, domestic automobile companies mainly rely on imported raw materials for production of steel for seat slides or slide rails. [0003] After searching, the Chinese patent No. ZL200510047632.4 "A Method for Manufacturing Low Carbon 700MPa ...

AI Technical Summary

Problems solved by technology

If hot-rolled steel is used, the thickness requirement cannot be met, and at the same time, the surface quality is also difficult to meet the requirement

The reference steel is micro-alloyed with Nb, V, Ti, and the content is very high. In addition, the Mn content is also high, so the weldability cannot meet the requirements.

The microstructure of steel in this comparative literature is ferrite + bainite, and the formability of this structure is insufficient

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