Vacuum Heat Treatment of H13 Steel Valve Hot Forging Die

---

Material: H13 steel

Technical requirements: 46 ~ 55HRC, bright surface, no oxidation and decarburization.

According to the technical requirements of valve forging die, vacuum heat treatment is the most reasonable. Generally, the process route of vacuum heat treatment of forging die is as follows: gasoline cleaning, forging die basket loading, 500 ~ 550 ° C x 90min primary vacuum preheating → 800 ~ 850 ° C x 60min secondary vacuum preheating → 1120 ~ 1140 ° C vacuum heating x 40min quenching heating and nitrogen filling quenching cooling hot water cleaning → 590 ~ 610 ° C x 240Min secondary vacuum high temperature tempering → quality inspection.

The hardness of the forging die after vacuum quenching and tempering is 49 ~ 53hrc, the whole is silver gray, and the cavity deformation is 0.03 ~ 0.05mm, which meets the size requirements. Practice has proved that the service life of the forging die after high temperature treatment in vacuum furnace is 3 ~ 10 times longer than that of low temperature treatment, and 2 ~ 3 times longer than that of salt bath treatment.

When the total amount of alloying elements of H13 steel forging die is less than that of 3Cr2W8V steel, the 1050C quenching heating temperature can not give full play to the properties of H13 steel material. Increasing the quenching temperature can improve the carbon content and alloying degree of austenite, and the decomposition of high-temperature tempered martensite, grain recrystallization growth and precipitation, aggregation and coarsening of carbide will be delayed and slowed down, Therefore, it ensures that the forging die has higher stability.

Considering that the H13 steel forging die itself is strongly impacted and has high requirements for thermal stability of the forging die, it is required to have high hardness and good wear resistance. Raise the heating temperature to about 1140 ° C to dissolve as many carbides as possible into austenite. The forging die can maintain high hardness, red hardness and sufficient strength.

H13 steel forging die should be quenched with hot oil, otherwise it will cause insufficient cooling and reduce the hardness of the matrix. It is easy to cause thermal wear and cavity collapse. When the matrix hardness is lower than 35hrc, it can not maintain the normal service needs.

Fig. 1 vacuum heat treatment process curve of M2 steel (American) drill bit

Learn more:

Vacuum Carburizing Of Small Diesel Engine Fuel Injection Needle Valve Body

Bevel Gear Ion Carburizing Process

Vacuum Heat Treatment Of W18Cr4V Steel Rolling Die

Copyright: SIMUWU Vacuum Furnace