Non-heat treated wire rod with excellent wire drawability and impact toughness and manufacturing method therefor

Abstract

Disclosed in the present specification are: a non-heat treated wire rod with excellent wire drawability and impact toughness suitable for use as a material for automobiles or a material for machine components; and a manufacturing method therefor. According to an embodiment of the disclosed non-heat treated wire rod, the wire rod contains, in weight percent, 0.05-0.35% of C, 0.05-0.5% of Si, 0.5-2.0% of Mn, 1.0% or less of Cr, 0.03% or less of P, 0.03% or less of S, 0.01-0.07% of sol. Al, 0.01% or less of N, at least one of 0.1% or less of Nb, 0.5% or less of V, and 0.1% or less of Ti, and the balance being Fe and inevitable impurities, and comprises, as a micro-structure, a ferrite-pearlite layered structure in a rolling direction.

Description

technical field [0001] The present disclosure relates to non-quenched and tempered wire rods and methods of making the same, and more particularly, to non-quenched and tempered wire materials suitable for use in vehicle or machine parts having excellent drawability and impact toughness wires and methods of making them. Background technique [0002] Most structural steels that have been used for machine structures or vehicle components are quenched and tempered steels that have improved strength and toughness through reheating, quenching and tempering processes after hot working. [0003] In contrast, non-heat-treated steel is steel that has a strength similar to that of heat-treated quenched and tempered steel without being subjected to heat treatment after hot working. Non-quenched and tempered wire rods have excellent economic viability by reducing manufacturing costs by omitting the heat treatment process involved in the manufacturing process of conventional quenched and...

AI Technical Summary

Problems solved by technology

However, as the drawability increases, the strength of the product increases but there is a problem of a rapid decrease in ductility and toughness

[0005] As a method to solve the above problems, a technique to obtain a bainite-based microstructure using expensive quenching elements such as molybdenum (Mo) and boron (B) has been reported, but due to the The deviation of physical properties caused by the non-uniformity of the bainite structure caused by the cooling deviation on the machine, so this technology is difficult to apply to commercial production

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