The invention relates to a steel PDC drilling bit with
erosion-proof tooth cavities which is used in the field of
petroleum and geological drilling. The steel PDC drilling bit with the
erosion-proof teeth comprises a drilling bit body and a knife wing, wearing
layers are welded on the front face and the back face of the knife wing, the tooth cavities are formed in the upper portion of the front face of the knife wing, and clad sheet
cutting teeth are arranged in the tooth cavities. The steel PDC drilling bit with the
erosion-proof tooth cavities is characterized in that cavity grooves are formed in the front ends of the tooth cavities along the edges of the tooth cavities, and wearing
layers are welded on the cavity grooves. According to the steel PDC drilling bit with the erosion-proof tooth cavities, the erosion-proof capacity of the front portions of the tooth cavities is enhanced, and thus the service life of the steel PDC drilling bit is prolonged. Further, more
welding material is coated on certain parts around the tooth cavities, the thickness of the wearing
layers is decreased gradually, the wearing layers around the tooth cavities are distributed reasonably, less
welding material is used, and the
machining cost of the drilling bit is decreased on the premise that the erosion-proof capacity of the tooth cavities is enhanced. Further, due to the fact that slopes which incline inwards are arranged on the back of the
nose part and the shoulder parts of the knife wing, the interference between the back side of rock debris and a well bottom face behind the knife wing is reduced effectively, the drilling resistance of the drilling bit is decreased, the
rock breaking efficiency of the drilling bit is improved, and the mechanical drilling speed of the drilling bit is increased.