METHOD OF THERMOCHEMICAL TREATMENT OF STEEL ISSUES Russian patent published in 1998 - IPC

FIELD: corrosion protection. SUBSTANCE: invention is designed to form corrosion- protection coating with black decorative color, for example, on outside surfaces of shooting arm. To that end, surfaces of steel parts are simultaneously saturated for 5-12 hr with nitrogen and carbon in heated to 500-600 C medium consisting of ammonia and natural gas or its partial combustion products. Then, molybdenum oxide saturation is carried out for 15 to 50 min in ammonium molybdate atmosphere overheated to 450-600 C. EFFECT: increased homogeneity of coating and its ability to resist wearing, and also increased diffusion reflection capacity of coating. 3 cl, 1 tbl