+（86）13543460072     Mon-Fri  8:00 a.m.-18:p.m.

 Iron and steel parts are generally tempered after quenching. Different working parts should be tempered at different temperatures in order to meet the requirements in use:
Cutting tools, bearings, carburizing and quenching parts, surface hardening parts are usually at 250 degrees Celsius under low temperature tempering. After low temperature tempering, the hardness changes little, the internal stress decreases and the toughness increases slightly.
When the spring is tempered at medium temperature of 350~500 DEG C, it can obtain higher elasticity and necessary toughness.
The parts made of medium carbon structural steel are usually subjected to high temperature tempering at 500~600 DEG C in order to obtain a suitable combination of strength and toughness.
When the steel is tempered at about 300 degrees centigrade, the brittleness is often increased. Generally should not be tempered in this temperature range. Some of the medium carbon alloy structural steel after high temperature tempering, if slowly to room temperature, but also easy to brittle. This phenomenon is known as the second kind of temper brittleness. The addition of molybdenum in steel, or tempering in oil or water, can prevent second types of temper embrittlement. The brittleness of the second kinds of tempered steel can be eliminated by heating it back to the original tempering temperature.
Steel plate quenching tempering heat treatment process:
Strip casting and quenching tempering process generally includes the following 3 stages:
1) heating the material to austenitizing temperature;
2) quenching is rapid cooling;
3) "tempering" is to heat the material to tempering temperature, and then slow cooling.