炭素鋼へのクロム基合金のレーザ肉盛り特性 Laser Beam Cladding Characteristics of Chromium-Based Alloy on Carbon Steel
CO<sub>2</sub> laser beam was applied to the cladding of chromium alloy using a beam scanner. The hardness and microstructure of the clad layer were investigated by changing the laser power, number of clad layers and overlapped width of the laser beam. The average hardness of the clad layer obtained was 550∼600 HV 0.1, when the conditions were; laser power of 2500 W to 2900 W, clad number of one layer to two layers (thickness of clad layer ; 0.85∼1.90 mm), overlapped width of 0.5 mm, cladding speed of 400 mm/min, defocusing distance of 30 mm, oscillated width of 7 mm and argon as the shielding gas. The microstructure of clad layer was completely transformed into a fine dendritic structure (secondary dendrite arm spacing ; 3∼5 μm) and eutectic structure by the rapid solidification conditions. A heat affected zone was produced on the surface of the carbon steel (base metal) and a martensitic structure could be observed. The heat affected zone was then heat treated also with CO<sub>2</sub> laser beam. The martensitic structure (700 HV 0.1) of the heat affected zone transformed into troostite. EPMA line analysis indicated that an alloyed layer (thickness ; 20∼30 μm) exists between the clad layer and base metal. These results show that CO<sub>2</sub> laser beam cladding of chromium-based alloy serves as a new surface treatment process for carbon steel.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 71(3), 159-164, 1999-03