What is the tempering after the surface hardening of stainless steel forgings?
Surface quenching of stainless steel forgings and ordinary quenching, induction heating surface quenching, generally need to be tempered after use, to reduce quenching stress and reduce brittleness, and sometimes adjust the surface hardness to reach the design requirements of the hardness range. However, the local induction surface quenching or flame surface quenching of large stainless steel forgings, the volume of stainless steel forgings is large, the weight is heavy, there is no large tempering furnace for overall heating, and sometimes the overall heating tempering of stainless steel forgings is also afraid of deformation.
Whether it is necessary to send stainless steel forgings into the furnace for overall tempering after surface quenching is a concern of heat treatment workers. Especially the very small local surface quenching range of stainless steel forgings, the residual stress is small, and the overall impact is small.
The surface quenching of stainless steel forgings can be partially tempered, self-tempered, or heated ceramic block far-infrared local tempering.
First, self-tempering.
Self-tempering, also known as "self-tempering", is the use of induction heating or flame heating to heat the heating surface, quenching is not cold to room temperature, the remaining heat is transferred to the quenching layer and the quenching layer area temperature rise for tempering.
Second, induction heating tempering.
Continuous moving induction hardening of stainless steel forgings, sometimes using induction tempering is more convenient, this tempering method can be carried out immediately after quenching. Because the tempering temperature is lower than the magnetic transition temperature, the penetration depth of the current is small.
Third, far infrared local heating tempering.
The far-infrared ceramic heater is attached to the surface heating part, and then the fire-resistant fiber board is attached to the outside of the heater, and the thermocouple is inserted between the heater and the surface of the stainless steel forging, you can control the heating temperature for local tempering, because the far-infrared ceramic heating block is assembled and flexible, it is assembled at any time according to the surface shape of the stainless steel forging, and the temperature control is direct. And can be controlled by microcomputer, tempering accuracy is very high. This method can solve the problem that the surface quenching of stainless steel forging products cannot be heated and tempered as a whole, and it is also more economical and convenient.