Medium carbon free-cutting non-quenched-and-tempered steel containing sulfur and tellurium and production technological method thereof

Abstract

The invention discloses medium carbon free-cutting non-quenched-and-tempered steel containing sulfur and tellurium and a production technological method thereof. The non-quenched-and-tempered steel mainly comprises 0.35%-0.50% of C, 0.10%-0.80% of Si, 0.75%-1.60% of Mn, 0-0.03% of P, 0.02%-0.08% of S, 0-0.08% of Mo, 0-0.025% of Nb, 0.02%-0.12% of V, 0.012%-0.016% of N, 0.02%-0.08% of Te, 0.001%-0.003% of Ca, and the balance Fe and inevitable impurities. The ratio of the tellurium to the sulfur is 0.25-2.5. According to the free-cutting non-quenched-and-tempered steel disclosed by the invention, occluded foreign substances in the steel can be subjected to modifying treatment by adding the tellurium, the cutting properties, fatigue resistance and the like of the non-quenched-and-tempered steel can be improved obviously, and pollution to the environment can be avoided.

Description

technical field [0001] The invention relates to a non-quenched and tempered steel and a production process thereof, in particular to a medium-carbon non-quenched and tempered steel and a production process thereof, which are applied in the technical field of iron and steel metallurgy. Background technique [0002] Non-quenched and tempered steel came into being under the background of the oil crisis in the 1970s. It canceled the quenched and tempered heat treatment by means of microalloying, controlled rolling and controlled cooling, and reached or approached the mechanical properties of quenched and tempered steel. A high-efficiency energy-saving steel. Since German Thyssen Company developed 49MnVS3 and applied it to automobile crankshafts, non-quenched and tempered steel has met the requirements of clean and reliable materials proposed by contemporary society by virtue of its advantages of no quenching and tempering, saving equipment investment, reducing production process...

AI Technical Summary

Problems solved by technology

[0012] The difficulty in the production process of free-cutting non-quenched and tempered steel is that during the continuous casting of sulfur-containing steel, the slab tends to stick to slag and crack, and it is easy to block the nozzle during continuous casting. The performance of free-cutting non-quenched and tempered steel prepared by the existing technology is not yet Ideal, but cannot meet the increasing requirements of the manufacturing industry for the machinability of materials

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