On 2018-08-08 14:48:54
Methods to reduce the cost of heat treatment process
Heat treatment refers to a kind of metal hot working process in which materials are heated, insulated and cooled in solid state to obtain the expected structure and properties. Metal heat treatment is a kind of technology which can heat the metal workpiece in a certain medium to a suitable temperature, keep it in this temperature for a certain time, and then cool it in different medium at different speeds, and control its performance by changing the microstructure of the metal surface or inside.
Metal heat treatment is one of the important processes in mechanical manufacturing. Compared with other processing technologies, Nantong heat treatment generally does not change the shape and overall chemical composition of the workpiece, but endows or improves the service performance of the workpiece by changing the microstructure inside the workpiece or the chemical composition on the surface of the workpiece. Its characteristic is to improve the internal quality of the workpiece, which is generally not visible to the naked eye. Therefore, it is a special process in mechanical manufacturing and an important part of quality management.
In order to make the metal parts have the required mechanical, physical and chemical properties, in addition to the reasonable selection of materials and various forming processes, heat treatment process is often essential.
The following are some experiences of heat treatment technicians on heat treatment cost reduction:
1. According to the requirements and conditions of parts, high quenching temperature shall be selected as far as possible to reduce the holding time. For Quenched and tempered 40Cr round steel (or similar low alloy structural steel), it can be seen that the workpiece will be water quenched directly after reaching the temperature (box furnace), without cracking.
2. The temperature uniformity of tempering furnace in well furnace is good, which can improve the tempering temperature and shorten the holding time. This requires rich practical experience. However, according to the production situation, the relationship between the charging capacity, the hardness after quenching, tempering time and tempering temperature can be determined through tests.
3. For single tempering, high temperature tempering is recommended. The furnace temperature after quenching can be used for direct tempering. It is recommended that the operators of Nantong heat treatment master such work experience at ordinary times.
4. For general carburized parts, if the requirements are not high, the carburizing temperature can be increased to 950 ℃, or higher, and then the sub temperature quenching.
5. The box type furnace is easy to use all fiber and coated with infrared paint to improve the heating speed.