Pre-hardening plastic die steel

Abstract

The invention relates to pre-hardening plastic die steel. The preparation method comprises the following steps: adding 0.05-0.15%V of microalloying elements into 4Cr2NiMnMo; after pleiotropic deformation, carrying out fine treatment and pre-hardening treatment, wherein the pleiotropic deformation comprises radial and axial forging deformation of the die steel and transverse and vertical pleiotropic deformation with the forging ratio greater than or equal to 8; the fine treatment comprises the following step: by taking the temperature of the forged die steel with the product thickness as a starting point, heating to 880+ / -10 DEG C; and after insulating at a speed of 3min / mm, discharging and air-cooling to 70 DEG C for spheroidizing annealing, wherein the specific process comprises the following steps: quickly heating to 780+ / -10 DEG C*3min / mm; and then cooling to 550 DEG C for discharging and air cooling at a speed less than or equal to 30 DEG C / h; the pre-hardening treatment comprises the following steps: heating the die steel with the product thickness from 70 DEG C to 350+ / -10 DEG C; insulating at the speed of 3min / mm; then heating to 880+ / -10 DEG C; then, insulating at the speed of 3min / mm; and then air-cooling to 70 DEG C and tempering.

Description

technical field [0001] The invention relates to a pre-hardened plastic mold steel, which belongs to the field of metal materials. Background technique [0002] The as-cast structure of the existing 4Cr2NiMnMo plastic mold steel is mostly coarse flaky F, P and a little M structure. According to the X-ray diffractometer test, F accounts for 85%, Fe 3 C accounts for 12%, and the rest is Cr 7 C 3 、Cr 23 C 6 Accounted for 3%. During thermal processing and heat treatment, Fe 3 C, Cr 23 C 6 、Cr 7 C 3 The solid solution of carbides into the matrix does not have a pinning effect, so the pre-hardened mold steel is prone to coarse flaky ferrite, sorbite and grain coarsening, which not only affects the corrosion resistance and corrosion resistance of the mold , and affect the performance of the mold. These factors hinder the application and development of 4Cr2NiMnMo. Contents of the invention [0003] The purpose of the present invention is to overcome the shortcoming of p...

AI Technical Summary

Problems solved by technology

During thermal processing and heat treatment, Fe 3 C, Cr 23 C 6 、Cr 7 C 3 The solid solution of carbides into the matrix does not have a pinning effect, so the pre-hardened mold steel is prone to coarse flaky ferrite, sorbite and grain coarsening, which not only affects the corrosion resistance and corrosion resistance of the mold , and affect the performance of the mold

These factors hinder the application and development of 4Cr2NiMnMo

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