A quenching method for forgings

Abstract

The invention provides a method for quenching a forged piece, wherein the method includes a quenching oil feeding box (1) and a quenching tank (7); the quenching tank (7) is internally provided with a conveying chain (9); the quenching oil feeding box (1) is connected with a first port (A) of a four-way makeshift valve (6) via a first bidirectional pump (3); a second port (B) of the four-way makeshift valve (6) is connected with the quenching tank (7); an oil return port (10) of the quenching tank (7) is connected to a third port (C) of the four-way makeshift valve (6) through a one-way pump (5); a forth port (D) of the four-way makeshift valve (6) is connected with a quenching oil return box (2) through a second bidirectional pump (4); the quenching oil return box (2) is connected with a quenching oil temperature regulator. The four-way makeshift valve (6) can change communication relationship of the quenching oil feeding box (1), the quenching tank (7) and the quenching oil return box (2), so that the device is suitable for a two-stage quenching process.

Description

technical field [0001] The invention relates to a quenching method for quenching a forging, in particular to a two-step quenching method using high-temperature and low-temperature quenching oil. Background technique [0002] One-time quenching will cause quality defects in many cases. For example, steel gear workpieces are quenched with 150°C quenching oil at 850°C to obtain phase transformation. Due to excessive temperature changes, the workpieces are easily deformed. The reason is that the stress and deformation are too large . [0003] figure 1 It is given that two-stage quenching is the existing technology in the field of quenching. Still taking the steel gear as an example, the first stage is heated at 850 degrees Celsius, and then quenched with 220°C quenching oil for the first time. The temperature of the workpiece drops sharply within T1, and T2 The steel gear gets a roughly uniform temperature within the time period, and the second-stage hardening is performed wit...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, the two-stage quenching is generally completed by two quenching equipment, which correspond to two different temperatures, which makes the equipment occupy a large area, and the pipeline for quenching oil is very complicated, and the inventor It is found that after the workpiece temperature is rapidly cooled in the first stage, the workpiece enters a temperature maintenance period, that is, T2 time. At this time, the temperature difference between the quenching oil and the surface of the workpiece is not much. The temperature is transmitted to the surface of the workpiece, but the efficiency of this heat exchange is very low, which is not conducive to the temperature reduction of the workpiece

Images