Explanation

In theory, pure iron is iron without carbon and any other impurities, but in fact it cannot be completely free of impurities, so pure iron usually refers to iron with low carbon and impurities. According to the purity, it can be roughly divided into three categories: Armco-iron (purity of 99.5%~99.9%), pure iron (purity of 99.90%~99.99%) and high purity iron (purity of 99.990%~99.997%). According to the production process, it can be divided into regional melting iron, electrolytic iron, hydrogen treated iron, Armco-iron and other pure iron with higher purity, lower strength, better ductility and better electromagnetic performance. The room temperature yield strength of iron without any impurities is only 53~57MPa. A very small amount of carbon can produce an obvious solution strengthening effect, while a small amount of sulfur and phosphorus can easily cause hot and cold embrittlement at a very low content. The mechanical properties of pure iron vary with the purity (especially carbon content) and grain size in a certain range, 98~116MPa, 176? 274MPa, A30%~60%, 70%~85%, hardness HB50~80. High purity iron is mainly used for research and making standard samples. pure iron with excellent magnetism can be used as electromagnetic materials, while pure iron with good plastic deformation can be used as deep drawing materials

Classification