(燕山大學(xué) 機械工程學(xué)院，秦皇島 066004)
摘 要: 對某廠生產(chǎn)中實際使用的鋁板鑄軋輥輥套進行解剖，采用金相顯微鏡、掃描電鏡及能譜分析等對表面裂紋和試件斷口形貌進行觀察。采用X射線衍射儀對裂紋中鋁的化合物屬性進行測量，分析鋁液對鑄軋輥輥套表面裂紋形成及擴展的影響；采用金相顯微鏡對輥套表面及內(nèi)部金屬組織進行對比觀察，分析高溫及復(fù)雜應(yīng)力作用對鑄軋輥輥套表面金屬組織性能的影響。結(jié)果表明：輥套表面裂紋起源于機械加工產(chǎn)生的微缺陷，鋁液對鑄軋輥表面腐蝕作用很小，但是滲入到裂紋中的鋁液凝固氧化后，相當(dāng)于在輥套表面金屬中嵌入高硬度的雜質(zhì)，在軋制過程中復(fù)雜應(yīng)力作用下將加快裂紋的擴展速度；高溫及復(fù)雜應(yīng)力作用對鑄軋輥輥套表面金屬組織的影響不大。
關(guān)鍵字: 鑄軋輥輥套；裂紋；熱疲勞；腐蝕；組織變性
（College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China）
Abstract: An actual shell of the casting roller was dissected for analysis. The cracks and cracked section were examined by metalloscopy and scanning electron microscopy with EDS mapping to investigate the mechanisms of the crack initiation and propagation. The quantify and characteristic of the compounds associated with Fe-Al were identified by X-ray diffractometry. The effect of the molten aluminum on the crack initiation and propagation on the casting roller surface was analyzed. The metal structure characteristics near the roller shell surface were contrasted to that in the shell interior using metalloscope, and the varieties by the action of the complex stresses and high temperature were analyzed. The results indicate that the crack is initiated in the manufactured defects on the roller surface, and the influence of the molten aluminum on corrosion behavior of the surface metal is little, but the molten aluminum may infiltrate into the cracks on the shell surface and becomes solidified and oxidized. The oxide is a kind of harder impurity inserted into the surface metal. The speed of crack propagation is accelerated when the shell surface subjects to the complex stresses in rolling process. The high temperature and the complex stresses have little effect on the microstructure of the roller shell surface.
Key words: casting roller shell; crack; heat fatigue; corrosion; structure characteristics
