Chemical elements of A333 Gr6:
- C element
C element can be solid solution in steel to form interstitial solid solution, the diffusion of carbon atoms in the heat treatment process or bias on the formation and distribution of carbide and steel properties have an important impact. Carbide is a hard phase, can improve the strength, hardness and wear resistance of steel, but is not conducive to the improvement of steel toughness, need to try to reduce the carbon content;
- Si, Mn element Si is the steel smelting process in order to remove the oxygen in the steel, Si helps to enhance the high-temperature deoxidation of steel as well as acid-etching resistance; Mn is a reinforcing element that can improve the hardness of the steel, wear-resistant properties and reversal of austenite stability, but Mn is easy to form MnS mixture with the S of the performance of the steel to bring about a bad influence;
- S, P elements from the elements of low-temperature toughness, generally believe that C, Si, P, S, N, etc. are harmful elements, and P is the most harmful, and Mn, Ni, etc. are beneficial elements. Therefore, ASTM A 333/A333M-2013 mainly rely on Mn to improve the low-temperature performance of Gr6, strict control of S, P content.
- Ni element Ni is an alloying element that promotes the stable existence of austenite, which is conducive to the improvement of steel plasticity and strength, and at the same time reduces the brittle-hard transition temperature of steel, and the nickel-rich reversed austenite can be preserved and stabilised at very low temperatures, which has an important influence on the improvement of the low-temperature toughness of A333Gr6. 2016 version of the later version of the A333GR.6 further enhances its low-temperature properties with the help of the new addition of Ni as well as alloying effect of V, Nb and so on. further enhanced its low-temperature properties.
