METHOD FOR SURFACE TREATMENT OF STEEL AND CAST IRON PARTS (VERSIONS) Russian patent published in 2002 - IPC

FIELD: mechanical engineering. SUBSTANCE: method involves surface nitriding of part by heating to saturation temperature in nitriding atmosphere; holding at said temperature; quenching part by heating in controlled atmosphere to temperature exceeding said saturation temperature; holding at said temperature and providing intensified cooling, as well as cold treatment of part and low-temperature tempering. According to first and second versions, part is held during surface quenching process at temperature ranging from 590 C to 727 C, and neutral or oxidizing atmosphere may be used as controlled atmosphere. According to second version, additional cooling of part is provided after termination of holding cycle during nitriding before subsequent heating during quenching process. Method may be used for surface treatment of different steel and cast iron parts operating under increased friction, wearing and corrosion conditions and provides for deformation-free treatment of parts having configuration of any complexity and rigidity. EFFECT: increased solidity, wear resistance, durability and corrosion resistance of treated parts. 3 cl, 3 dwg, 2 ex