Three elements and core of forging heat treatment process

The heat treatment process of forgings makes the materials get good properties, which is a key process in mechanical manufacturing industry. Heat treatment process is one of the important means to make the metal materials get good properties. Forging heat treatment is a processing process in which steel is forced in solid state, heated to a predetermined temperature, kept for a certain time, and then cooled in a certain way. Its technological process is: heating - heat preservation - cooling.

The purpose of metal heat treatment is to improve the local or overall properties of metal materials and products. Heat treatment process is the process of heating a metal to a predetermined temperature to hold it for a certain time and then cooling it. For the heating of steel, "temperature" is the first important, is also the most sensitive, the accurate determination of temperature is the first step of heat treatment. The length of "heating time" is related to different types of steel, furnace type, furnace loading, etc. Some people do not attach great importance to this, often only measured from the hardness, but other mechanical properties often have potential unqualified factors, only after use can know the quality of heat treatment. "Speed" is the most difficult and very important link to master in the process of heat treatment engineering. It needs a long time of practical training and exploration to master this skill, and it needs a good theoretical basis as support to improve. The microstructure transformation of the heat treatment process includes: the heating transformation of steel parts, the theoretical basis is the iron-carbon phase diagram; The cooling transformation of steel, including pearlite transformation, martensite transformation, bainite transformation, tempering transformation, the theoretical basis is CCT, TTT and hardenability curve. The parameters of heat treatment, such as heating temperature, holding time and cooling mode, which are formulated according to the law of microstructure transformation of steel, are heat treatment process parameters.

The three elements in heat treatment process are temperature, time, and (heating and cooling) speed. These three elements run through the whole process of operation skill training of heat treatment technical workers or technical personnel, which is the key to the success of heat treatment process personnel. ① the basic structure state of iron-carbon phase diagram, the balance transition process of iron-carbon alloy, the application range of iron-carbon phase diagram; (2) Microstructure transformation during continuous heating; (3) Microstructure transformation of austenite during cooling and various methods of obtaining microstructure.