Heat treatment technology for die-casting die steel

Abstract

The invention relates to a heat treatment technology for die-casting die steel. The steps of heat treatment are as follows: 1. quenching: loading raw material into a furnace at 550 DEG C, preserving heat for 40 min; heating to 1,150 DEG C, preserving heat for 110-130 min, and then discharging the raw material and cooling the raw material with oil to room temperature; 2. tempering: tempering the raw material three times, with the heating temperature of 560-700 DEG C and the heat preservation time of 90 min in each tempering. according to the heat treatment technology, as the quenching temperature rises, the quenching hardness is improved, more carbide is dissolved, the austenite alloying extent is increased, and thus martensite is strengthened; tempering that is performed once in the traditional technology is performed three times, so that residual low-hardness austenite in the material is fully changed into high-hardness secondary martensite to improve the mechanical property of a die. The service life of the die treated according to the heat treatment technology can reach 4,500 times, the cost of the die is lowered and the production efficiency is increased.

Description

technical field [0001] The invention belongs to the technical field of high-speed steel processing, and relates to a heat treatment process of steel for die-casting molds. Background technique [0002] 3Cr2W8V steel is the typical steel type for the die-casting mold. The carbon content is not high, but due to the high content of tungsten and chromium, the structure still belongs to hypereutectoid steel. It is designed according to the basic alloying scheme of "low carbon high speed steel". Carbon is the main element that guarantees a certain hardness. Since die-casting molds generally work under harsh working conditions of up to 1200 °C, the blank metal flows in the mold cavity under strong pressure and impact load during work, and the blank metal and the cavity produce severe friction, which easily wears the surface of the cavity; at the same time The forging die must work under the condition of repeated cooling. Due to the result of alternating cold and heat, the surface...

AI Technical Summary

Problems solved by technology

Therefore, wear and fatigue are the main forms of die-casting mold failure. Die-casting molds processed by traditional processes have a low service life, with an average use of 1500 times. The mold cost is high, and frequent mold replacement affects production efficiency.