A kind of grain-refined cold heading steel and its production process

Abstract

The invention discloses cold heading steel with refined crystalline grains and a production process thereof. The cold heading steel comprises, by weight, 0.32-0.38% of C, 0.10-0.35% of Si, 0.60-0.90% of Mn, 0-0.20% of Cr, 0-0.030% of P, 0-0.035% of S, 0-0.20% of Ni, 0.010-0.040% of Al, 0.050-0.080% of Ti, 0-0.30% of Cu and the balance Fe and inevitable impurities. The production process of the cold heading steel comprises smelting, continuous casting and rolling. According to the cold heading steel with the refined crystalline grains and the production process thereof, the elements of the Al and the Ti are added, so that the material crystalline grains are refined, and the structure is more uniform; meanwhile, reasonable timing for using the Al and adding the Ti is chosen, then molten steel deoxidizing is strengthened, and finally the cold heading property of the cold heading steel is greatly improved by improving the purity of molten steel and the grain size of the material.

Description

technical field [0001] The invention belongs to the field of metallurgy, and relates to a grain-refined cold heading steel and a production process thereof. Background technique [0002] Due to its excellent cold forming performance, cold heading steel materials have adopted cold drawing technology in the machining industry to replace the traditional cold cutting technology of hot rolled materials. The main advantages of this new technology are: saving a lot of man-hours and improving production efficiency At the same time, it can save a lot of energy, thereby reducing environmental pollution; in addition, the metal consumption rate of materials can be reduced by about 20%, which meets the requirements of clean production and resource-saving enterprise production; and the obtained products have relatively high dimensional accuracy. The surface finish is good, and it is a rapidly developing machining process that has emerged in recent years. The fastener products produced by ...

AI Technical Summary

Problems solved by technology

[0004] SWRCH35K is a kind of cold heading steel with wide application and high performance requirements. It is suitable for producing 8.8-10.9 high-strength bolts, nuts, flange bolts and hexagon socket bolts. In order to meet the requirements of use, SWRCH35K needs to have a high cold top Forging performance, currently domestically produced SWRCH35K can only achieve 1 / 2 cold upsetting qualification, and it is difficult to guarantee 1 / 3 cold upsetting qualification, so how to improve the cold upsetting performance of SWRCH35K has become a major difficulty in the industry

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