Free-cutting steel containing relatively high content tin and preparation method

Abstract

The invention discloses free-cutting steel containing relatively high content tin, and belongs to the technical field of metallurgy. The free-cutting steel is characterized in that the problem that at present, the tin content is too high, so that the hot shortness of free-cutting steel is too high is solved by conducting alloying of Mo, W and a rare earth element, that is, La on the free cutting steel. The free-cutting steel comprises the following basic chemical elements in percentage by mass: 0.02-0.77 percent of C, 0.01-0.10 percent of Si, 0.30-1.50 percent of Mn, 0-0.035 percent of S, 0-0.025 percent of P, and 0.05-0.35 percent of Sn, also comprises the main alloying elements in percentage by mass: 0.2-0.75 percent of Mo, 0.4-2.25 percent of W, and 0.002-0.020 percent of a rare earth element, that is, La, and further comprises the rest ingredients of Fe and inevitable impurities. The alloying process of Mo, W and the rare earth element La is mainly realized in the refining process. The free-cutting steel has relatively high hot rolling process performance and relatively high rolled metal surface quality when having high cutting performance, and is a low-sulfur and lead-free environmental-friendly material meeting the development tendency.

Description

technical field [0001] The invention relates to a free-cutting steel with relatively high tin content, which belongs to the technical field of metallurgy. Background technique [0002] With the development of the national economy, the number of automatic machine tools has increased rapidly, and its application range has also expanded. At the same time, due to the adoption of new cutting tools and new processes, the cutting speed is increasing day by day, and the surface roughness and precision of various machined parts are required to be stricter. Therefore, the machinability of steel is generally valued. Countries are competing to develop steels with excellent machinability - free-cutting steels. At present, the main consuming countries of free-cutting steel are all developed countries, and the consumption of free-cutting steel in my country is still very small, but it is constantly expanding. Free-cutting steel is widely used in automobiles, tractors, motorcycles, aviati...

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Problems solved by technology

[0008] At present, there is no research on the addition of Mo, W, and rare earth element La to the composition of free-cutting steel, especially in the aspect of using these alloy elements to inhibit the segregation of free-cutting element Sn along the austenite grain boundary to improve the performance of hot rolling process. public report

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