Alloy steel for low temperature vacuum carburizing

Abstract

The present invention relates to an alloy steel for low temperature vacuum carburizing, and more particularly, to an alloy steel for low temperature vacuum carburizing, wherein, where the thermal processing of carburizing and quenching is performed at 810° C. or so of an available minimum carburizing temperature of a conventional vacuum carburizing furnace, it is able to securing an adequate ferrite phase (α) to improve the thermal distortion according to the thermal processing of an annulus gear, and to satisfying shape restrictions such as a roundness or a cylindricity of the annulus gear to be manufactured. An alloy steel for a low temperature vacuum carburizing according to the present invention, the alloy steel is composed of a chief element of Fe, wherein the alloy steel is formed so that dissolved oxygen (DO) is 10 ppm or less in an alloy system which comprises 0.17˜0.24 weight percent of C, 0.8˜1.2 weight percent of Cr, 0.4˜0.8 weight percent of Mn, 0.80˜1.20 weight percent of Si, 0.020 weight percent or less of P, 0.020 weight percent or less of S, 0.015˜0.045 weight percent of V, and the remaining weight percent of Fe.

1 . An alloy steel for a low temperature vacuum carburizing, the alloy steel being composed of a chief element of Fe, wherein the alloy steel is formed so that dissolved oxygen (DO) is 10 ppm or less in an alloy system which comprises 0.17˜0.24 weight percent of C, 0.8-1.2 weight percent of Cr, 0.4-0.8 weight percent of Mn, 0.80-1.20 weight percent of Si, 0.020 weight percent or less of P, 0.020 weight percent or less of S, 0.015-0.045 weight percent of V, and the remaining weight percent of Fe. 
     
     
         2 . An alloy steel for low temperature vacuum carburizing, the alloy steel comprising 0.17˜0.24 weight percent of C, 0.8-1.2 weight percent of Cr, 0.4-0.8 weight percent of Mn, 0.80-1.20 weight percent of Si, 0.020 weight percent or less of P, 0.020 weight percent or less of S, 0.015-0.045 weight percent of V, and the remaining weight percent of Fe. 
     
     
         3 . The alloy steel for low temperature vacuum carburizing of  claim 2 , wherein the alloy steel is formed so that dissolved oxygen (DO) is 10 ppm or less. 
     
     
         4 . An alloy steel for low temperature vacuum carburizing, the alloy steel comprising Fe, wherein the alloy steel is formed so that dissolved oxygen (DO) is 10 ppm or less. 
     
     
         5 . The alloy steel for low temperature vacuum carburizing of  claim 4 , wherein the alloy comprises 0.17˜0.24 weight percent of C, 0.8-1.2 weight percent of Cr, 0.4-0.8 weight percent of Mn, 0.80-1.20 weight percent of Si, 0.020 weight percent or less of P, 0.020 weight percent or less of S, 0.015-0.045 weight percent of V, and the remaining weight percent of Fe.