CN104372351A - Heat treatment method for die-casting mould - Google Patents

Abstract

The invention discloses a heat treatment method for a die-casting mould. The heat treatment method for the die-casting mould comprises the following steps: (1) heating the die-casting mould to the temperature of 1,020-1,050 DEG C at the speed of 50-100 DEG C per hour, carrying out heat preservation for 20-50 minutes, and then, cooling at the speed of 150-200 DEG C per hour; (2) cooling the die-casting mould, treated in the step (1), to the temperature of -60 DEG C to -70 DEG C, and carrying out heat preservation for 2-3 minutes; (3) introducing a nitrogen source and a carbon source at the temperature of 550-600 DEG C, so as to carry out carburizing and nitriding treatment on the die-casting mould treated in the step (2), reacting for 3-8 hours, then, tapping and naturally cooling. According to the heat treatment method disclosed by the invention, the cracking of the carburized and nitrided die-casting mould during repeated die-casting can be obviously reduced; compared with the general methods, the heat treatment method has the advantage that the service life of the die-casting mould can be doubled or so.

Description

A kind of heat treating method of transfer mold

Technical field

The present invention relates to a kind of transfer mold, particularly H13 Heat Treatment Of Steel method.

Background technology

H13 steel is transfer mold steel most widely used at present, usually adopts carburizing, nitridation process to improve its surface hardness, but easily causes the decline of thermal crack resistant ability when thermal treatment, in press casting procedure repeatedly, easily occur be full of cracks.

Summary of the invention

The technical problem to be solved in the present invention overcomes existing defect, provides a kind of heat treating method of transfer mold.

In order to solve the problems of the technologies described above, the invention provides following technical scheme:

A heat treating method for transfer mold, comprises the steps:

(1) transfer mold is risen to 1020-1050 DEG C with the speed of 50-100 DEG C/h, be incubated after 20-50 minute, cool with 150-200 DEG C/h speed;

(2) transfer mold after step (1) process is cooled to-60 ~-70 DEG C, insulation 2-3 minute;

(3) at 550-600 DEG C, pass into nitrogenous source and carbon source the process of carburizing nitrogen is carried out to the transfer mold after step (2) process, react after 3-8 hour, come out of the stove, naturally cooling.

The be full of cracks occurred in press casting procedure repeatedly after heat treating method of the present invention obviously can reduce transfer mold carburizing nitrogen, compared with general method, the present invention can improve transfer mold access times about 1 times.

Embodiment

Below in conjunction with preferred embodiment, the present invention will be described, should be appreciated that preferred embodiment described herein is only for instruction and explanation of the present invention, is not intended to limit the present invention.

embodiment 1

The transfer mold of H13 steel is added in quenching furnance, nitrogen atmosphere, rise to 1020 DEG C with the heat-up rate of 100 DEG C/h with stove, be incubated 20 minutes, with the speed furnace cooling of 150 DEG C/h.

By cooled transfer mold deep cooling to-60 DEG C, be incubated after 3 minutes, naturally rise to room temperature.

Again transfer mold is put into vacuum oven, nitrogen atmosphere, be warmed up to 550 DEG C with stove, then pass into ammonia/methyl alcohol (volume ratio is 1:1), stop logical ammonia/methyl alcohol after 4 hours, furnace cooling.

embodiment 2

The transfer mold of H13 steel is added in quenching furnance, nitrogen atmosphere, rise to 1030 DEG C with the heat-up rate of 50 DEG C/h with stove, be incubated 50 minutes, with the speed furnace cooling of 200 DEG C/h.

By cooled transfer mold deep cooling to-70 DEG C, be incubated after 2 minutes, naturally rise to room temperature.

Again transfer mold is put into vacuum oven, nitrogen atmosphere, be warmed up to 600 DEG C with stove, then pass into ammonia/methyl alcohol (volume ratio is 1:2), stop logical ammonia/methyl alcohol after 4 hours, furnace cooling.

Last it is noted that the foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, although with reference to previous embodiment to invention has been detailed description, for a person skilled in the art, it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein portion of techniques feature.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (1)

1. a heat treating method for transfer mold, comprises the steps:

(1) transfer mold is risen to 1020-1050 DEG C with the speed of 50-100 DEG C/h, be incubated after 20-50 minute, cool with 150-200 DEG C/h speed;

(2) transfer mold after step (1) process is cooled to-60 ~-70 DEG C, insulation 2-3 minute;

(3) at 550-600 DEG C, pass into nitrogenous source and carbon source the process of carburizing nitrogen is carried out to the transfer mold after step (2) process, react after 3-8 hour, come out of the stove, naturally cooling.