Used by different cooling medium, vacuum quenching oil quenching can be divided into the vacuum, vacuum gas quenching, vacuum and vacuum nitrate water quenching austempering. Die vacuum heat treatment in the main application of vacuum oil quenching, vacuum gas quenching and vacuum annealing. In order to maintain work (such as molds) excellent characteristics of vacuum heating, cooling agent and cooling process of selection and development is very important, die quenching process is mainly oil-cooled and air-cooled. After the heat treatment for longer machining die breast, 450h steel, using as much as possible after quenching and tempering vacuum, especially vacuum hardening of the workpiece (mold), which can improve the surface quality-related mechanical properties such as fatigue properties, surface brightness, and corrosive. Quality carbon structural steel ① steel beginning of the two figures that the carbon content of steel, the average carbon content of the very few that, for example, the average carbon content of 0.45% steel, steel number "45", Hefei h steel, It is not a sequence number, it can not be read as 45 steel. ② high manganese content of high-quality carbon structural steel, 200c steel, manganese should be marked, h steel prices, such as 50Mn. ③ boiling steel, semi-killed steel and special-purpose high-quality carbon structural steel should last particularly marked in the steel, for example, the average carbon content of 0.1% of the semi-killed steel, the steel No. 10b. 125h steel | Fair Commerce Bo (certified) | h beam provided by Hefei Hefei Show Bo Trading Company. Hefei Show Bo Trading Company (www.hfzhanbo.com) (www.hfzhanbo.com) is Hefei, steel leaders, over the years, the company implement the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customers needs. In the exhibition of Commerce Bo leadership with the staff warmly welcome all inquiries negotiations to create the exhibition of Commerce Bo better future.