Rolling technique of lead treated steel

Abstract

The invention belongs to the field of metallurgy and relates to rolling process of lead-containing free-machining steel. A rolling mill is used for rolling, in the rough rolling process, the rolling temperature is controlled at 1030-1060 DEG C, the former three-pass material form is reduced 1-3mm based on the standard material form; in the intermediate rolling process, the roll material form is the standard material form, and the rolling temperature is controlled at 980-1030 DEG C; in the pre-finish rolling process, the roll material form is the standard material form, the rolling temperatureis controlled at 1060-1030 DEG C, and the temperature of the rolled piece reaches 1005-1040 DEG C after the pre-finish rolling process; in the finish rolling process, the temperature of the rolled piece in a finishing mill is less than 980 DEG C, the roll material form is the standard material form, and the rolling temperature is controlled at 1020-1050 DEG C. The rolling process can prevent steel heaping caused by the cleavage crack of the cold, hot and frailty susceptible head of the rolled piece, prevent sliding accident caused by the high temperature of the steel, steadily increase the yield of the lead-containing free-machining steel, obviously reduce the waste, and greatly reduce the 100t steel fault time.

Description

technical field [0001] The invention relates to a rolling process in the field of metallurgy, in particular to a rolling process of lead-containing free-cutting steel. Background technique [0002] With the rapid development of industries such as national machining and precision instruments, the requirements for processing materials are constantly increasing, so as to ensure the surface finish of products. The development of lead-containing free-cutting steel satisfies the needs of the processing industry well. In order to smooth rolling The rolling process of lead-containing free-cutting steel wire rod and billet is of great significance to whether the production can be carried out normally. Lead-containing free-cutting steel belongs to S and Pb composite free-cutting steel. The steel contains relatively high S and Pb, and its high-temperature plasticity is poor. Even if the heating process is strictly controlled during production, if the rolling process is not strictly con...

AI Technical Summary

Problems solved by technology

In the existing rolling process of lead-containing free-cutting steel, due to the temperature difference between the core and the surface of the billet, stress is generated, which will cause the head to bloom during the rolling process, resulting in steel stacking accidents

The standard material type adopted by the rolling mill in the rough rolling area is not suitable for the production of lead-containing free-cutting steel, which increases the probability of pile-up accidents caused by blooming of the head, and reduces the yield rate and economic benefits of lead-containing free-cutting steel