Manufacturing method of cold-rolled medium-high carbon alloy structural steel with thickness ranging from 0.1 mm to 0.4 mm

Abstract

The invention discloses a manufacturing method of cold-rolled medium-high carbon alloy structural steel with the thickness ranging from 0.1 mm to 0.4 mm. The cold-rolled medium-high carbon alloy structural steel is prepared from components in percentage by weight as follows: 0.25%-0.55% of C, 0.15%-0.35% of Si, 0.10%-2.0% of Mn, 0.10%-2.0% of Cr, 0.010%-0.030% of Alt, less than or equal to 0.015% of P, less than or equal to 0.005% of S, no more than 0.3% of other added alloy elements and the balance of Fe and inevitable impurity elements. The manufacturing method comprises steps as follows: smelting, refining, continuous casting, heating, finish rolling, pickling, cold rolling, intermediate annealing, cold rolling, intermediate annealing, cold rolling and finished product annealing. Through control on inclusions in the steel, three times of cold rolling and three times of annealing, a cold-rolled medium-high carbon alloy structural steel strip with the thickness ranging from 0.1 mm to 0.4 mm is obtained. The total reduction rate of first-time cold rolling and second-time cold rolling is controlled to be larger than or equal to 50%, and the single-pass reduction rate is larger than or equal to 10%, so that lamellar carbide in different areas are crushed, the carbide is evenly separated out in the shape of fine particles through long-time low-temperature intermediate annealing, the strength is further reduced, and the plasticity is further improved.

Description

technical field [0001] The invention relates to the technical field of steel manufacturing, in particular to a method for manufacturing cold-rolled medium-high carbon alloy structural steel with a thickness of 0.1-0.4 mm. Background technique [0002] Medium-high carbon alloy structural steel is widely used in various industries such as hardware, home appliances, tools, stone processing, automobiles, textiles, etc. After cold rolling to 0.1-0.4mm, precision parts such as small springs, valve plates, and chains can be manufactured. Surface quality, composition uniformity, inclusions, etc. all have high requirements. [0003] The prior art discloses "a cold-rolled diaphragm spring steel for automobiles and its production method", specifically disclosing a cold-rolled diaphragm spring steel for automobiles and its production method, the composition and weight percentage of which are C: 0.40-0.65%, Si: 0.15-0.35%, Mn: 0.60-1.00%, P≤0.010%, S≤0.007%, Alt≤0.040%, Ni: 0.20-0.50%, ...

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Problems solved by technology

[0004] This application provides a method for manufacturing cold-rolled medium-high carbon alloy structural steel with a thickness of 0.1-0.4mm, which solves the problem that the cold-rolled product of medium-high carbon alloy structural steel in the prior art is relatively thick and cold-rolled to a thickness below 0.4mm. It is prone to quality problems of fracture, peeling, and holes. The reduction rate of a single cold rolling is low, resulting in incomplete penetration of deformation, and no annealing after the end of cold rolling, and the technical problems of poor formability of the steel strip.

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