Cold work roll steel for high-strength steel rolling, cold work roll and its manufacturing method

Abstract

The invention discloses cold work roll steel for high-strength steel rolling, a cold work roll and its manufacturing method. The material of cold work roll is composed of the following chemical components of: by weight, 0.6-0.8% of C; 0.6-1.5% of Si; 0.6-1.5% of Mn; 4.0-6.0% of Cr; 0.5-2.0% of Mo; 0.5-1.0% of V; P being less than or equal to 0.020%; S being less than or equal to 0.015%; and the balance being Fe and unavoidable impurities. The manufacturing process comprises steps of: electric furnace smelting; secondary refining; vacuum degasification; electric bar casting; electroslag refining; ingot casting; forging; preheat treatment; rough machining; quenching and tempering treatment; semi-finish machining; final heat treatment; finish machining; and finished product. According to thenovel cold work roll provided by the invention, the ratio of the alloy elements is optimized based on 5% of Cr. By the adoption of a short-time high-temperature solid solution quenched-tempered heat treatment technology, the roll strength and wear resistance of the cold work roll are improved, thus satisfying production requirements of high-strength cold rolled strips.

Description

technical field [0001] The present invention relates to the field of metallurgy. Specifically, the present invention relates to a cold-rolled work roll and a manufacturing method thereof, and more specifically to a cold-rolled work roll steel for high-strength steel rolling, a cold-rolled work roll and a manufacturing method thereof . Background technique [0002] With the rapid development of industries such as automobiles, home appliances, and food, high-strength steel series products have become an important part of steel companies building cold-rolled products. Their main features are: the yield strength of finished strip steel reaches 1400MPa, and the highest tensile strength reaches 1600MPa. This makes the high strength of rolled products put forward higher requirements on the performance of cold-rolled work rolls, making the selection of cold-rolled work rolls for high-strength steel rolling a difficult problem. [0003] The high-end cold-rolled work roll steel curre...

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Problems solved by technology

[0004] The Chinese invention patent with the patent publication number "CA1282983C" has a low Cr content, so that the depth of the hardened layer obtained by it is not enough, and the low content of Mo and V cannot form special carbides that are beneficial to wear resistance; the patent The invention patent with publication number "JP2000246315A" has low C content and relatively high content of Cr and Mo, which makes the martensitic matrix unable to achieve optimal hardness and strength; The C content of the patent is too high, and the formed matrix is ​​mainly twinned martensite, which makes the toughness of the cold rolling roll insufficient; and the patent publication numbers are "JP10317102A", "JP9041091A", "JP2002285284A", "JP1208437A" and "JP2001279366A" The invention patent of the invention not only has high C content, but also high Cr, Mo or other alloy elements (V, W, etc.), which is not conducive to the forging of larger-sized cold rolls, and there are certain difficulties in manufacturing. The patent publication number is The invention patent of "JP2001279366A" and its cold rolling roll manufacturing method are Nippon Steel's patented continuous electroslag casting process (CPC), which is a non-traditional forging process

[0005] It can be seen from the above that the main problems exposed by the existing cold-rolled work rolls currently used for high-strength steel rolling are poor wear resistance and insufficient strength of the roll body, while performance indicators such as wear resistance and strength are related to the microstructure of the material. There is a close relationship. Through the improvement of the material of the roll and the optimization of the heat treatment process, the microstructure of the material can be improved, the wear resistance of the roll can be improved, and the best match of strength and toughness can be achieved.

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