Forging and thermal treatment technique for Cr12MoV steel

Abstract

The invention discloses a forging and thermal treatment technique for Cr12MoV steel. The forging and thermal treatment technique specific for Cr12MoV steel comprises the following working procedures that a PLC four-point temperature-controlled regenerative heating furnace is selected and applied, and the heating process is divided into three stages, specifically, heating is carried out till the temperature is 550 DEG C firstly, the temperature is increased from 550 DEG C to 850 DEG C at a uniform speed, the temperature increasing speed is kept to be 80-90 DEG C per hour, the temperature is kept at 850 DEG C for eight hours, and then the temperature is increased to 1100-1150 DEG C; the initial forging temperature is 1100-1150 DEG C, and the final forging temperature is 850-880 DEG C; oil or salt bath quenching is carried out till the temperature is 1100-1150 DEG C, and the temperature is preserved for 15 min; cooling is carried out; three sections of isothermal spheroidizing at the temperatures of 720 DEG C, 740 DEG C and 720 DEG C separately are carried out, and each section lasts for two hours; tempering is carried out at the temperature of 220 DEG C; and the steel is discharged out of a furnace and placed in air for natural cooling. Processing molds for the technique can make carbide refined, edges and corners round and Austenite matrixes superfine, and high hardness and compressive strength are achieved.

Description

technical field [0001] The invention relates to a process in the technical field of forging, in particular to a forging process. Background technique [0002] Cr12MoV steel is a high-Gr micro-deformation cold work die steel widely used in my country. It belongs to ledeburite steel. The structure of eutectic carbide dendrites is very developed. These carbides are characterized by high melting point, hard and brittle, and extremely poor plasticity. The thermal conductivity of this steel is poor, and there are two contradictory factors at work in the forging process. On the one hand, the carbides are broken up by the blow of the forging hammer. If the final forging temperature is too low, the austenite is seriously deformed and Work hardening occurs, on the other hand, the forging temperature is high, the melting point of the eutectic carbide accumulation is low, the hammering is too strong, the forging temperature rises to make the local microscopic area of ​​the workpiece ris...

AI Technical Summary

Problems solved by technology

In production, often because the traditional process cannot eliminate large eutectic carbides or severe network carbides, the molds made of this material will crack after being used for less than the expected number of times after being put on the machine. During use, the cracks expand rapidly, and the mold fails and cannot be used less than the expected number of times