Development and Production of Seamless Steel Pipe for TP550RD Rotary Digging Machine Drill Pipe

Introduced in this paper is the development and production of seamless steel pipe for TP550RD rotary digging machine drill pipe.Satisfying products are made as per application requirements of manufaturers of drill pipes for rotary digging machine by taking actions such as designing reasonable chemincal composition, strictly controlling the chemincal composition, the steel purity and the inclusion content in steel-making, adopting PQF pipe-rolling process, and applying a heat treatment process including quenching at 920℃ for 30 min, tempering at 680℃ for 60 min and air cooling.The results of the experiments and applicaions show that the seamless steel pipe for TP550RD rotary digging machine drill pipe has high weldability and dimension precision, excellent mechanical properties and good low temperature toughness.The pipe ductile-brittle transition temperature is below-50℃, which can meet the low temperature impact toughness requirement on drill pipe for rotary digging machine working at extremely cold areas, increasing the service life of the drill pipe to more than 3 000 h.