STEEL PIECES HARDENING METHOD Russian patent published in 1995 - IPC

FIELD: structural materials and pieces surfaces thermal treatment by highly concentrated streams of energy. SUBSTANCE: piece surface is multiply heated up to temperature of hardening by pulses of heavy-current electronic beam with pulse duration of (0,5-3)·10^-6 s, electron energy of 10 50 keV, power spectral density of 2-5 J/cm² and interval between pulses of no less than τ₀= [N·q/ρ·c(T₁- T₀)]²/a, with N number of pulses; q beam power density, J/cm², ρ, c, a correspondingly density in kg/cm³, special thermal capacity in J/kg·K and factor of steel heat conductivity in cm²; T₀ initial temperature of piece in C, T₁ temperature of steel tempering in C. Preliminary piece surface is applied with coating of refractory metals nitrides. After treatment by heavy-current electronic beam pieces are dipped in liquid medium with temperature of T ≅ 120 K. EFFECT: increased pieces surfaces hardening. 3 tbl