According to different technical requirements, the 09MnD, 09MnNiD seamless steel pipes for low temperature heat exchanger which produced by our company, have been tightened the content of the iVl n and Scompared with the GB150-1998. The content of S is less than 0.015%, while the actual content is below 0.010%. Besides, by referring to the corresponding regulations of the GBB531-1996, we increased the requirements of the content of acid soluble aluminum in steel, which narrowed the range of the tensile strength and improved the requirement for the stability of The steel pipes.
The 09MnD, 09MnNiD seamless steel pipes of the same technical requirements have very dose chemical composition of each furnace and good low-temperature impacting property. The molten steel of low temperature in production has high purity and its grain size is greater than level 8. With the perfect testing equipment, we can ensure the stability of quality of assembly line production seannless steel pipes.
The seamless steel pipes also have the characteristics of high cleanliness, reasonable proportion of the chemical composition and scientific heat treatment system, etc. Therefore, the steel weldability and manufacturing has increased significantly, which accords with GB151-1999, the manufacturing standard of heat exchanger. The impact value on this series of steel in actual detection at-50℃ and -70℃ is much higher than the requirements of enterprise and nat onsl standards.The 09MnD,09MnNiD seamless steel pipes for low-temperature service are mainly used in low-temperature heat exchanger in the coal chemical, petrochemical, ethylene and polypropylene device, etc.