FIELD: percussion drilling, particularly couplings and joints between rod and bit, or between rod and rod provided with ribs, pins, jaws, complementary grooves or the like.
SUBSTANCE: drill member comprises sections of decreased thicknesses and thread including working thread profile sides, bottom and thread profile tops extending between working thread profile sides and formed of two different materials. Drill member is made as composite component. Thread bottoms are made of stainless steel. Thread profile tops are formed of low-alloyed steel. Composite component is provided with flush channel. Method for drill member production involves producing core and sleeve, wherein one part is made of stainless steel, another one is formed of low-alloyed steel; inserting core into the sleeve; welding thereof to retain core inside the body; making thread so that thread bottoms are formed of stainless steel.
EFFECT: improved resistance to corrosion fatigue in sections having decreased thicknesses and at thread bottom of drill member.
10 cl, 11 dwg, 1 ex, 1 tbl
Authors
Dates
2007-07-10—Published
2003-02-18—Filed