Novel chromium system hot die steel and thermal treatment process thereof

Abstract

The invention relates to novel chrome hot work die steel belonging to hot work die steel, particularly relating to the hot work die steel with low content of tungsten and the thermal treatment process thereof. The hot work die steel comprises 0.35-0.7 percent of C, 0.3-1.3 percent of Si, 0.3-1.3 percent of Mn, 7.0-11.0 percent of Cr, 0.4-1.2 percent of W, 0.4-1.2 percent of Mo, 0.4-1.2 percent of V, 1.0 percent of Ni, 0.005 percent or less of S, 0.030 percent or less of P, 0.03 percent of-0.10 percent of B, equal to or more than 0.02 percent and equal to or less than 0.20 percent of nitride, equal to or more than 0.02 percent and equal to or less than 0.10 percent of N, and the rest of Fe by weight percent. The steel of the invention has finer crystal grain, generates greatly increased heat resistance, toughness and compressive strength and has more than three times of durable frequencies than the existing die steel. The invention further provides the thermal treatment process with relatively low steel quenching temperature of 1020-1050 DEG C.

Description

technical field [0001] The invention belongs to a hot work die steel, in particular to a hot work die steel which uses a large amount of chromium Cr and reduces the use of molybdenum Mo and vanadium V and its heat treatment process. Background technique [0002] Hot work die steel requires materials with high hardenability, high temperature strength, high wear resistance, high toughness, high thermal cracking resistance and high melting loss resistance. In the United States, hot work die steel is divided into three types: chromium hot work die steel, tungsten hot work die steel and molybdenum hot work die steel, all of which are crowned with the letter H, respectively denoted as H10~H19, H21~H26 and H42, H43 Wait. Among them, the carbon content of the first two steels is in the range of (0.30-0.50)%, the carbon content of the latter steel is in the range of (0.50-0.70)%, the total of Cr, W, Mo and V alloy elements of the three steels The content is in the range of (6-25)%....

AI Technical Summary

Problems solved by technology

The invention adopts a special time-controlled rapid cooling process, which not only avoids the risk of cracking in brine quenching, but also greatly improves the quenching quality, effectively improves the impact toughness of H13 steel after tempering, and thus greatly improves the service life of the mold. However, the proportion of various materials has not been changed, and the material cost is relatively high

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