本研究探討經熱處理、深冷處理及高速火焰熔射碳化物噴覆處理之 鎳鉻鉬鋼耐磨特性變化。JIS SNCM 220 及JIS SNCM 415 分別經滲碳到 有效硬化層深度為0.6 mm,再進行深冷處理;JIS SNCM 439 進行淬火 回火熱處理到45HRC;再分別經熔射噴覆(HVOF)到厚度約125±25μm 之WC/Co 塗層。由實驗結果得知,經HVOF 噴覆WC/Co 塗層硬度介於 1025±75HV 之間。處理試片進行荷重95.9N,轉速為180rpm 之塊材對 輥輪(Block-on-Roller)乾式磨耗試驗,其中對磨輥輪硬度有60 及42HRC 二種。由磨耗結果顯示,以 60HRC 為對磨材經12h 磨耗,滲碳SNCM 220 試片經深冷處理,磨耗損失量由滲碳未深冷之0.05g 降至0.03g,表面 WC/Co 噴覆處理後,磨耗損失量由0.03g 再降至0.002g。滲碳SNCM 415 試片經深冷處理後,由滲碳未深冷之0.05g 降至0.025g,表面WC/Co 噴 覆處理後,磨耗損失量由0.025g 再降至0.002g;淬火回火熱處理SNCM 439 試片經WC/Co 噴覆處理後,磨耗損失量由0.045g 降至0.002g,顯 示深冷處理及HVOF 處理後均能有效提升表面硬度及降低鋼材磨耗損 失。
This study was performed in order to investigate the wear behavior of NiCrMo steel with/without sub-zero treatment and carbide coating. The JIS SNCM 220 and JIS SNCM 415 steels were carburized and a JIS SNCM 439 steel was quenched and tempered to 45HRC. The WC/Co coating about 125μm thick was coated on surface of the three steels by the high velocity oxy-fuel (HVOF) spray. The experimental results indicate that microhardness of the WC /Co coating were found to be 900~1200 HV0.3. The wear testing was conducted under 95.9N with 180 rpm at the type of block-on-roller. From the results of 12hr wear tests, the mass loss of sub-zero treatment SNCM 220 specimen was decreased from 0.05g to 0.03g. The mass loss of carbide coated SNCM 220 specimen by the HVOF spraying was decreased from 0.03g to 0.002g. The mass loss of sub-zero treatment SNCM 415 specimen was decreased from 0.05g to 0.025g. meanwhile, the mass loss of carbide coated SNCM 415 specimen by the HVOF spraying was decreased from 0.025g to 0.002g. The mass loss of SNCM 439 specimen by the HVOF was decreased from 0.045g to 0.002g. Therefore, the HVOF spraying can improve the surface hardness and wear resistance of steel.