Abstract: 00Cr30Mo2 is a steel material with a ferritic stainless steel structure. It has good stress corrosion resistance and comprehensive mechanical properties. It is most widely used in parts such as petroleum and gas products and power plant components that require corrosion resistance and high temperature strength.
1 Introduction
00Cr30Mo2 is a ferritic stainless steel with a chromium content of more than 18%, a carbon content of 0.06-0.09% and a molybdenum content of 2-2.5%. It is added with niobium to enhance its corrosion resistance and thermal stability, and is used as an excellent structure material for parts in the petrochemical industry and power industry.
2 Main Characteristics and Applications
2.1 Main Characteristics
00Cr30Mo2 has good anti-fatigue and stress corrosion resistance, and has relatively higher thermal strength. It has a hardness of less than 213HB with high formability, and it has a better high temperature oxidation resistance than ordinary stainless steel. It is a kind of high temperature resistant material which is suitable for heating processing such as quenching and tempering. The strength and hardness of this steel material are not very high, so it is easy to process and can withstand relatively high temperatures and shocks.
2.2 Applications
Due to the excellent properties of 00Cr30Mo2, it is widely used in the parts of petroleum and gas products and power plant components, such as steam turbine blades, steam turbine flow path components, various valves and petrochemical process pumps. Especially for sulfur-bearing oil production and high-rate nitrate water injection and other corrosive media processes, 00Cr30Mo2 can be used as a material to reduce corrosion and potential accidents caused by corrosion.
3 Heat Treatment
00Cr30Mo2 can be subjected to hot working and cold working. After forming, it can be heat-treated to obtain the desired strength and hardness. The commonly used heat treatment process includes soft solution treatment, quenching and tempering, and martensitic precision casting process. The optimal temperature of solution treatment is 1050℃ (122℉) to 1100℃ (1292℉). For quenching and tempering, the temperature is controllable, the quenching temperature is 850℃ (1562℉), and the tempering temperature ranges from 590℃ (1094℉) to 650℃ (1202℉). If temper temperature is higher than 650℃ (1202℉), it will lead to grains and brittle tissue. After solution treatment or quenching and tempering, it is necessary to carry out aging treatment or tempering, the aging temperature is 620℃ (1148℉).
4 Welding
00Cr30Mo2 can be welded by common welding methods, such as manual arc welding, gas welding, submerged arc welding, tungsten arc welding, electroslag welding and plasma welding etc. To obtain satisfactory welding performance, proper welding parameters and welding materials should be selected according to different welding methods. Sufficient welding heat is necessary to form a complete and continuous welding interface. In order to ensure the welding quality, the welding rod should be stored in a dry place and dry it before use. In order to fully protect the welded joints, preheating and postweld heat treatment are also recommended.
5 Summary
In conclusion, 00Cr30Mo2 has good stress corrosion resistance, comprehensive mechanical properties and thermal stability. It is an excellent structure material for the parts of petroleum and gas products and power plant components, such as steam turbine blades, steam turbine flow path components, various valves and petrochemical process pumps. Its weldability is good, and the heat treatments such as solution treatment and quenching and tempering can be used to obtain the desirable strength and hardness for parts. In order to guarantee the welding quality, the welding parameters and materials should be reasonably chosen.
