Research On The High Strength Drilling Pipe Manufacturing Technology

Coal mine gas preventing and controlling is an important foundation work of safetyproduction.Gas extraction is a fundamental measure in preventing gas accident.The drillingrod is the important tool of gas drainage boreholes, which must have the better mechanicalproperties and requirements for the bad conditions.But in this kind of work, the drilling rodhad some problems, mainly manifested the male joint root break, the thread serious distortion,the thread gluing and unusual attrition.In order to solve these problems this project startedresearch.The paper uses the methods of combing with the theory and practice, to improve the overallperformance of the ordinary drilling rod and develop the higher strength drilling rod. Themajor contents of this project are optimizing overall performance of drilling rod,studying on heat treatment technology of thread surface, andimproving the process technique.In the part of overall performance optimization of drilling pipe, the mechanical properties ofjoints improved by choosing optimal, changing transformation and heat treatment process，and verified by finite element method.In the part of thread surface treatment craft research, Itis comparing the common surface treatment methods，and using nitriding process to improvethe surface hardness of thread in order to prevent galling.And it determines the reasonableparameters and summarizes a set of process specifications by deeply studying the nitridingprocess.In the part of the optimization of drilling rod processing craft, we adjust the existingprocessing craft, and develop a set of high strength drilling rod processing craft to adapt to therequirement of mass production. Finally some pips and connector samples are produced totest static torque, and it verified its performance has reached the design requirements.The project finally develops a kind of φ63.5mm high strength drilling rod, whose jointsoverall performance are enhanced.The new rod can withstand a certain torque more than 10000Nm, which solved some problems about the thread wearing and gluing. It also canconstruction with the great torque drilling machine, specially the ZDY3200S drilling machine,and a set of complete technology process about the high strength drilling rod production aresummarized.