METHOD AND COMPOSITION FOR BOROCHROME PLATING OF STEEL PRODUCTS IN FLUIDIZED BED Russian patent published in 2000 - IPC

FIELD: thermochemical treatment. SUBSTANCE: method includes boronizing of steel products in mixture containing boron carbide and corundum at temperature of 650- 1000 C for 10-90 min, and chrome plating in mixture containing chrome and corundum at 900-950 C for 20-90 min. Composition for boronizing of steel products contains the following components, wt.%: boron carbide 10-20; ammonium chloride 0.01-0.1; sodium tetrafluoroborate 0.02-0.05; the balance, corundum. Composition for chrome plating of steel products contains, wt. %: chrome 1-10; ammonium chloride 0.01-01; the balance, corundum. EFFECT: obtained quality diffusion layers with high microhardness and corrosion resistance, saved components of saturated mixture, and reduced time of process duration. 3 cl, 1 tbl, 1 ex