Effects of Alloying Elements on the Wear Resistance of SK85 High-Carbon Tool Steel

[[abstract]]高碳工具鋼由於熱處理後有較高的硬度、一定的耐磨性，加之其機械加工性能好、價格便宜，在機械製造中常被廣泛用於製造木工刀具、工模具等，高碳工具鋼含碳量高但未添加合金元素時，硬化能較差，採用油淬得不到理想的组織及耐磨耗性，採用水淬可得到較高的硬度及耐磨耗性但工件變形量大且有淬裂的危險。添加Cr、Mo合金元素可提高其硬化能，提高油淬之麻田散鐵比例及耐磨耗性，因此本研究規劃以熔軋後之SK85、SK85+0.15wt%Cr、SK85+0.25wt%Cr、SK85+0.15wt%Cr+0.20wt%Mo、SK85+0.20wt%Mo及SK85+0.40wt%Mo等6種成分設計之熱軋鋼料(厚度5.0mm)進行耐磨耗試驗評估比較。研究項目包括：(1) 耐磨耗試驗鋼材前處理之淬回火試驗參數建立，(2) 在相同淬回火硬度下，不同鉻鉬合金成分設計SK85鋼材之耐磨耗性質評估與比較，(3) 鉻鉬合金碳化物晶體結構、析出位置及型態之TEM與X-ray解析及(4) 鋼材組織耐磨耗機構之建立。[[abstract]]Due to high hardness and wear resistance, high carbon tool steel is widely applied in woodworking tools. High carbon tool steel with poor hardenability can not achieve good microstructure and wear resistance through the oil quenching process. Although high carbon steel can be well hardened by water quenching, dimensional change and quenching cracking are concerned. The hardenability of high carbon steel can be approved by the addition of molybdenum and chromium. With alloying elements addition higher martensite percentage and good wear resistance can be obtained. In this study wear resistance of SK85, SK85+0.15wt%Cr, SK85+0.25wt%Cr, SK85+0.15wt%Cr+0.20wt%Mo, SK85+ 0.20wt%Mo, and SK85+0.40wt%Mo are analyzed. The aims of this study are (1) to establish the heat-treatment parameters for quenching and tempering processes, (2) to analyze the effects of Cr and Mo on the wear resistance (3) to observe the size and distribution of carbide by TEM and X-ray (4) to establish the wear mechanis