Die isothermal forging conditions

Under normal production conditions, the anti-location strength of the die material at the working temperature should reach 3 to 5 times the flow stress of the forging material at the forging temperature, and the die life has the value of production application.

Currently, the isothermal forging process is the main forming method for advanced difficult-to-deform materials (such as titanium alloys, nickel-based superalloys, intermetallic compounds, etc.), and it is also used for the extrusion of hot work die steel mold cavities. The principle is to heat the blank and the mold to the same temperature, and deform the blank at a very low strain rate (10-4s-1~10-2s-1), because the mold chill and material strain hardening are eliminated. Influence, the deformation resistance of the material is small, and the near-net shape processing can be completed, thereby greatly improving the utilization rate of the metal and the performance of the forging.

The superplastic extrusion temperature of the die cavity of hot work die steel is 700℃~750℃, the temperature of isothermal forging and superplastic forging of titanium alloy is mostly 800℃~900℃, and the temperature of nickel-based alloy is mostly about 1000℃ The isothermal forging temperature of nickel-based powder alloys is usually above 1050℃, while the isothermal forging temperature of TiAl intermetallic compounds is above 1100℃.

In this temperature range, the mold must have: high high temperature strength; high wear resistance and certain high temperature hardness; excellent heat fatigue resistance and oxidation resistance; appropriate impact toughness; better hardenability And thermal conductivity.