Mold selection to meet the process performance requirements

The manufacture of molds generally have to go through several processes such as forging, cutting, heat treatment. In order to ensure the manufacturing quality of the mold, reduce production costs, the material should have good malleability, machinability, hardenability, hardenability and grindability; should also have a small oxidation, decarburization sensitivity and quenching deformation cracking tendency. 
1. Hardenability Hardenability is defined as the depth of the hardened layer and hardness distribution of the specimen under the specified conditions to characterize the material, which depends mainly on the size of the material's critical quenching cold speed. The property that determines the depth of hardening and hardness distribution of a steel under specified conditions. That is, the ability of steel quenching to get the size of the depth of the hardened layer, which indicates the ability of steel to accept quenching. Steel hardenability good and poor, commonly used hardening layer depth to indicate. The greater the depth of the hardened layer, the better the steel hardenability. The hardenability of steel is an inherent property of the steel itself, which depends only on its own internal factors and has nothing to do with external factors. The hardenability of steel depends mainly on its chemical composition, especially the alloying elements containing large hardenability and grain size, heating temperature and holding time and other factors. Good hardenability of steel, can make the entire cross-section of the steel parts to obtain uniform and consistent mechanical properties as well as the choice of steel quenching stress quenchant to reduce deformation and cracking. 
2. Oxidation, oxidation: in a narrow sense, the chemical reaction between elemental oxygen and other elements of matter, called oxidation, is also an important chemical unit process. 
Oxidation in a broader sense, refers to the loss of electrons (oxidation number of elevated) process, the human metabolism is also like oxidation, that is, the human body is rusting every day, the rust produced in the medical science is called free radicals.