METHOD OF FORMING STRENGTHENED LAYER OF PART Russian patent published in 1998 - IPC

FIELD: METAL WORKING. SUBSTANCE: invention relates to mechanical treatment of metals followed by heat treatment and can be, in particular, used to manufacture long-length guiding satellites, which are flexible transportation means in automated assembly-welding lines. Objective of invention is creating, in wear direction of part, strengthened layer with any needed thickness and high hardness allowing considerable deformations when being formed, which are further eliminated with no loss in wear resistance and workability of part. This objective is achieved by forming, on surface of part to be strengthened, specially oriented alternating cavities and swellings with specified depth, profile, and spacing, which are then subjected to surface hardening, after which swelling apexes are removed thereby providing magnitude of residual distortion. Depth of cavities (h₁≥ h+2δ₂-δ₁) is specified from the following relationship: h₁, where h is allowable wear of part, δ₂ residual distortion value, and δ₁ magnitude of hardened value of part in direction of normal to the surface profile. Profile of the cavities represents isosceles triangle with apex radius and spacing specified from the following relationship: , where α aperture angle of cavities; h, δ₁, and δ₂ are defined above; R cavity apex radius; t swelling and cavity spacing; P_sp allowable specific pressure; P loading (force) acting on part surface; a is part surface width; and l is length of part surface contact. Surface hardening further involves cementation followed by high-frequency current hardening. Cavities and swellings are oriented in direction of relative displacement of part being in contact with part under consideration. EFFECT: increased wear resistance. 5 cl, 3 dwg