On 2018-08-08 14:48:54
Development and application of heat treatment
Heat treatment is a kind of metal hot working technology which can heat, heat and cool the metal material in a certain medium, and control its performance by changing the metallographic structure on the surface or inside of the material. Since the 20th century, with the development of metal physics and the application of other new technologies, metal heat treatment technology has been greatly developed.
A remarkable progress is that from 1901 to 1925, the rotary hearth furnace was used for gas carburizing in industrial production; in the 1930s, the dew point potential difference meter appeared, which made the carbon potential of the atmosphere in the furnace controllable, and later, the methods of further controlling the carbon potential of the atmosphere in the furnace were studied, such as carbon dioxide infrared meter and oxygen probe; in the 1960s, the heat treatment technology used the role of plasma field, and the ion carburizing was developed With the application of laser and electron beam technology, new methods of surface heat treatment and chemical heat treatment have been obtained.
After heat treatment, aluminum plate can strengthen alloy, which has good formability, weldability, machinability and medium strength. It can maintain good operability after annealing. It is mainly used in mechanical structure, including bar, plate, pipe and profile.
Seamless aluminum tube is a typical duralumin alloy in aluminum copper magnesium system. Its composition is reasonable and its comprehensive performance is good. Many countries produce this alloy, which is the largest amount of duralumin.
Seamless aluminum tube has high strength and certain heat resistance, which can be used as working parts below 150 ℃. When the temperature is higher than 125 ℃, the strength of 2024 alloy is higher than that of 7075 alloy. The formability is better in the hot state, annealing and new quenching state, and the heat treatment strengthening effect is significant, but the aluminum tube has strict requirements for heat treatment process.