Novel high-service life die-casting mold steel and process method for manufacturing aluminum-magnesium die-casting mold

Abstract

The present invention relates to the field of die-casting mold materials, particularly to a novel high-service life die-casting mold steel and a process method for manufacturing an aluminum-magnesium die-casting mold, wherein the die-casting mold ally steel elements comprise, by mass, 0.15-0.18% of C, 12-14% of Cr, 5-7% of Mo, 9-11% of Co, 0.35% of V, 0.25-0.45% of Nb, less than 0.015% of S, less than 0.010% of P, and the balance of Fe. The aluminum-magnesium die-casting mold manufacturing process method comprises: steel ingot smelting, forging, preheat treatment, machining, strengthening heat treatment, finish machining and final inspection. According to the present invention, according to the working temperature of the aluminum-magnesium die-casting mold and the failure mode during use, the correlation and the process of the material science, and effects of various elements on the material performance are comprehensively utilized to rationally design the material components of the die-casting mold steel, such that thermal stability, corrosion resistance, wear resistance, thermal fatigue resistance, thermal conductivity and other properties of the die-casting mold are significantly improved so as to improve the service life of the die-casting mold.

Description

technical field [0001] The invention relates to the field of die-casting die materials, in particular to a novel high-life die-casting die steel and a process method for manufacturing aluminum-magnesium die-casting dies. Background technique [0002] Light alloy materials such as aluminum-magnesium alloys have been valued by the manufacturing industry because of their high specific strength and atmospheric corrosion resistance, and have become the preferred materials for many mechanical parts. Manufacturing aluminum-magnesium parts with complex shapes by die-casting technology has the characteristics of energy saving, material saving, less pollution, less process and high efficiency, so it has been widely used, and the number of uses is increasing year by year. However, in the production process of die-casting parts, the production stoppage and the decline in the pass rate of the parts caused by mold damage (fracture, wear, crack, corrosion, plastic deformation, etc.) are be...

AI Technical Summary

Problems solved by technology

[0005] (1) Poor thermal stability: When the die-casting mold is working, the temperature of the liquid aluminum-magnesium alloy in the cavity is about 700-850°C, and the actual temperature of the working surface of the mold is as high as 600-700°C. The hot hardness and hot strength are greatly reduced, so it is easy to undergo plastic deformation and lose its effectiveness;

[0006] (2) Poor corrosion resistance: Under the above working temperature of the die-casting mold, the surface of the mold cavity is prone to chemical reactions with liquid aluminum or magnesium alloy, release agent and air, so that the material on the surface of the mold cavity is prone to dissolution or impurity infiltration , leading to a decrease in the surface roughness of the mold, and a decrease in the size and quality of the product;

[0007] (3) Poor wear resistance: At working temperature, when the mold surface is in contact with the die-casting alloy and its slag particles for a long time, friction and abrasive wear are prone to occur, which changes the size of the mold cavity, resulting in a change in the size of the workpiece or out-of-tolerance ;

[0008] (4) Poor thermal fatigue: when the die-casting mold is working, it must be repeatedly heated (liquid alloy injection) and cooled (spray release agent after the part is taken out), and the mold surface will generate thermal fatigue under the action of alternating temperature and form cracks. resulting in rough surface of the workpiece;

[0009] (5) The thermal conductivity is not ideal: when the liquid alloy is injected into the working surface of the die-casting mold, the temperature of the mold surface increases rapidly, and sometimes when the temperature is higher than the tempering temperature of the mold, the mold is plastically deformed and fails; moreover, the mold temperature is high, When cooling, the temperature difference is large, the internal stress generated is large, and thermal fatigue cracks are prone to occur

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