Easy-cutting untempered steel and method for manufacture thereof

Abstract

The invention discloses a Ca-S composite free-cutting non-quenched and tempered steel for cutting which has high cutting property and the manufacturing method thereof. The steel is composed of 0.44% to 0.49% of C, 0.30% to 0.60% of Si, 1.20% to 1.50% of Mn, 0.08% to 0.12% of V, no more than 0.30% of Cr, Ni and Cu, 0.040% to 0.065% of S, no more than 0.035% of P, 0.001% to 0.010% of Ca, 0.01% to 0.03% of Al, and the balance Fe and unavoidable impurity. According to the method, the compositions of inclusion in steel are controlled by ladle argon blowing and Ca-S composite processing, casting blank is poured by continuous casting, the average temperature for heating billet in a heating furnace is 1180 DEG C to 1220 DEG C, the heating time is 2 to 3 hours, the rolling starting temperature is 1100 DEG C to 1150 DEG C, the rolling finishing temperature is 850 DEG C to 1000 DEG C, the cooling speed of the rolled steel is 1.5 DEG C per second to 2.5 DEG C per second, the cooling bed cooing in pile temperature is 600 DEG C to 700 DEG C. The steel has superior mechanical property and free-cutting property.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to a free-cutting non-quenched and tempered steel and a manufacturing method thereof, in particular to a Ca-S composite free-cutting non-quenched and tempered steel with high cutting performance and a manufacturing method thereof. Background technique [0002] Non-quenched and tempered steel is a mechanical structural steel that can meet the performance requirements without quenching and tempering treatment. Using this kind of steel to manufacture parts can save the quenching and tempering heat treatment process and equipment, and at the same time, avoid the waste products generated during the heat treatment process, reducing It reduces pollution and reduces energy consumption. This kind of steel is an energy-saving steel. my country is rich in resources such as vanadium and titanium, and the development of non-quenched and tempered steel is not only in line with my country's nation...

AI Technical Summary

Problems solved by technology

[0008] Aiming at the deficiencies of the prior art, the present invention provides a Ca-S composite free-cutting non-quenched and tempered steel with high cutting performance, which mainly solves the cutting performance problem of low-sulfur free-cutting non-quenched and tempered steel under high-speed cutting conditions, and is extremely Greatly improved mechanical properties

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