Introduction to Spheroidal Graphite: Spheroidal graphite is obtained from nodular cast iron through spheroidization and inoculation treatment, effectively improving the mechanical properties of cast iron, especially improving plasticity and toughness, thereby obtaining higher strength than carbon steel. Ductile iron is a high-strength cast iron material developed in the 1950s, with comprehensive properties similar to steel. Based on its excellent performance, it has been successfully used to cast some parts with complex stress, high requirements for strength, toughness, and wear resistance. Ductile iron has rapidly developed into a widely used cast iron material, second only to gray iron. The so-called "replacing steel with iron" mainly refers to ductile black cast iron.
Petroleum pipe (GB948-88) is a seamless steel pipe suitable for furnace pipes, heat exchangers, and pipelines in petroleum refineries. Geological drilling steel pipe (YB235-70) is a steel pipe used by geological departments for core drilling. It can be divided into drill pipes, drill collars, core pipes, casing pipes, and sedimentation pipes according to its purpose; Petroleum pipe is a long steel strip with a hollow cross-section and no seams around it, while petroleum cracking pipe is an economic cross-section steel.

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