METHOD FOR PRODUCTION OF COATINGS Russian patent published in 2018 - IPC B23K20/08 C23C26/00 

FIELD: blasting.

SUBSTANCE: invention relates to technology for production of coatings on metals using the energy of explosives and can be used in the manufacture of parts for energy and chemical plants with enhanced heat resistance. The pack is prepared for welding with a symmetrical arrangement between two aluminium plates with 1.5-2 mm thickness, the plates of tri-metal are plates of alloyed steel on both sides with clad low-carbon steel. The thickness of said plate is chosen not less than 3 mm, the thickness of its cladding layers is within 0.3-0.5 mm. The same explosive charges are arranged on the two sides of the pack on the surfaces of aluminium plates, and explosion welding is carried out by explosion with simultaneous initiation of detonation in charges. Detonation velocity in each explosive charge equals to 2000-2700 m/s, the explosive charge height and the welding gaps between the metals to be joined are selected from the condition to obtain impact velocity of aluminium plates with the cladding layers of low carbon steel of the tri-metal plate within 370-490 m/s. Thermal treatment of welded five-layer blank to form solid intermetallide diffusion interlayers between aluminium layers and the layers low-carbon steel is carried out at 660-665°C for 0.7-1 H. Then it is cooled with the furnace to temperature 640-650°C. Holding is carried out at this temperature for 2-3 hours with subsequent air cooling up to spontaneous separation of aluminium layers from low-carbon steel of intermetallide diffusion layers with formation of solid heat-resistant coating from intermetallides of aluminium-iron system on the surfaces of low-carbon steel layers.

EFFECT: provided simultaneous production of intermetallic coatings on both sides of said tri-metal plate having high heat resistance, low roughness amplitude with reduced susceptibility to crack formation during heat changes without the use of deficient and expensive nickel in the process scheme, with reduced number of explosion welding operations up to one.

2 dwg, 1 tbl, 4 ex