PURPOSE: To produce a nickel alloy product excellent in mechanical strength and galling resistance by forming a nickel alloy product from a nickel alloy material by cold heading and then forming a nitrided and hardened layer on the surface of this product.
CONSTITUTION: A nickel alloy product prepared by applying cold heading to a nickel alloy material (Ni-Cr, Ni-Co-Mo, etc.) is heated and held to and at about 350-600°C under the fluoride gas atmosphere where NF3, BF3, etc., are used and concentration is regulated to about 10000-100000ppm, by which N atoms are allowed to penetrate uniformly into the surface of the product. Then this product is heated and held to and at about 500-700°C for about 3-6hr under the nitriding atmosphere where, e.g. a gaseous mixture of NH3, CO, and CO2 is used, by which a dense and uniform nitrided and hardened layer of about 2-50μm thickness is formed. By this method, the nickel alloy product excellent in mechanical strength and galling resistance and having a nitrided and hardened surface can be obtained.
| JPS60228794 | ROTARY COMPRESSOR |
SENBOKUTANI HARUO
KITANO KENZO
HAYASHIDA TADASHI
MINATO TERUO
