Tempering and tempering treatment
The quenching and tempering heat treatment of automobile parts can be divided into protective atmosphere quenching and tempering heat treatment and general quenching and tempering heat treatment. Protective atmosphere heat treatment can ensure that the parts in the heat treatment process will not produce surface oxidation, decarburization and other defects, to ensure the surface quality of parts. When the working face of parts after quenching and tempering treatment needs subsequent processing, general heat treatment is adopted. According to the quality and size of the parts, the heat treatment equipment has mesh belt furnace, casting chain furnace, plate (basket) push rod furnace, bracket furnace, suspended continuous furnace.
Induction heat treatment
Compared with general furnace integral heating and heat treatment, induction heat treatment has the following characteristics:
(1) according to the performance requirements of the product, only the surface or local heating of parts, surface or local strengthening is implemented, so it is an energy-saving heat treatment.
(2) the production process is pollution-free and is a clean heat treatment.
(3) the induction heating time is short and the speed is fast, which is conducive to refining the quenching structure and obtaining the strengthening effect with good wear resistance and torsion and bending fatigue resistance.
(4) the induction quenching device can be easily installed in the production line, facilitating production management and reducing logistics costs.
(5) induction quenching production has fast beat, high efficiency and can be fully automated.
The characteristics of induction heat treatment make induction quenching technology widely used in automobile parts production. At present, the induction hardening of automotive parts is mainly the transmission of power torque automotive shaft parts, such as crankshaft, half shaft, spline shaft, transmission shaft, camshaft and various pin shaft parts.
Forging waste heat treatment
Most automobile structural parts are formed by hot forging. It is an important energy saving measure how to use the heat treatment of forging blank. If isothermal annealing and quenching are adopted, the microstructure and hardness required for subsequent processing can be obtained, saving energy and energy consumption of reheating heat treatment. The spare heat treatment parts are various gear blank, front axle, steering knuckle, rocker arm, spline shaft, crankshaft, connecting rod and so on. In order to ensure the microstructure and hardness uniformity of the forging waste heat treatment, it is necessary to strictly control the final forging temperature, intermediate cooling process, isothermal temperature and so on. Parts of hardening, strong performance, in order to ensure the parts in addition to the direct quenching process, also can use precooling to 550 ~ 650 ℃, the completion of pearlite transformation, heating again to austenitizing temperature method. The main purpose is to refine the structure and obtain good toughening performance.
Non - annealed cold heading steel and non - tempered steel
In order to guarantee the cold forming property of cold heading steel, the material needs to be spheroidized annealing in advance. Cold heading steel without annealing can be directly used in cold heading forming by adjusting the chemical composition of cold heading steel, controlling the rolling and cooling technology in the rolling process, making part of pearlite spheroidized and metamorphosed and reducing the deformation resistance in the cold forming process. Because spheroidizing annealing is avoided, it has remarkable energy saving effect and shortened production cycle.
Non quenched and tempered steel due to strong joined the trace of carbon in steel (nitrogen) compound forming elements (V, Nb, Ti, etc.), produced in the process of controlled cooling after forging and forging precipitation strengthening and grain refinement effect, its strong performance can be achieved or close to the level of the quenched and tempered steel, and eliminating the tempering heat treatment process, reduce a large number of energy consumption and good processability, brought to the attention of the many car manufacturers at home and abroad. For example, German Benz, Volkswagen, Swedish Volvo automobile company, British business in, American G.M, ford automobile company, Italian fiat automobile company makes engine crankshaft, connecting rod, front axle and other important parts in a large number with non-quenched and tempered steel. Japan is ahead of the world in the research and application of non-quenched and tempered steel. For example, the hot forgings used in the steering system and transmission system of mitsubishi motors are almost all made of non-quenched and tempered steel, and the crankshaft and connecting rod of nissan and 50-ling motors are almost all made of non-quenched and tempered steel. For more than ten years, dongfeng motor company has used non-quenched and tempered steel to produce crankshaft, connecting rod, automobile front axle, steering knuckle and other parts. With tens of thousands of tons of non-quenched and tempered steel annually, millions of automobile parts such as crankshaft, connecting rod and front axle have been produced accumulatively, and remarkable economic and social benefits have been achieved.
Heat treatment equipment for auto parts
Heat treatment has become an indispensable and increasingly important processing method in modern industry. So the development of induction heating equipment is growing. Choose good heating equipment, can make work twice the result with half the effort. There are several kinds of heat treatment equipment for auto parts commonly used in industry