Recently, the steel pipe company successfully trial produced 2 furnaces of rotary excavator key bar steel for the first time to meet the needs of the market and users.

The internal and external keys of the drill pipe of the rotary excavator are the key parts to transmit the pressure and torque during the actual operation of the drill pipe. At present, most of the internal and external key materials of domestic rotary excavator drill pipe are short of service life due to low strength and poor wear resistance. The bainite key bar pipe steel for rotary excavator developed by steel pipe company and customers has high strength and toughness, good wear resistance, and can save manufacturing process and reduce production cost.

Due to the high alloy content of the steel, high requirements for cleanliness of molten steel, strict requirements for gas and harmful elements in steel, smelting and continuous casting production are difficult. On the basis of fully mastering the laboratory research of steel grade material characteristics, the technical personnel of R & D center and steel branch plant estimate and judge the control difficulties and attention problems in production, formulate feasible operation points of converter, refining, continuous casting and other processes, and successfully complete the trial production.

The melting composition, macrostructure and internal and external surface quality of the steel for the key bar tube of the rotary excavator can meet the requirements of the users for the key bar pipe, and has strong product advantages and market competitiveness.