采用自约束热疲劳试验方法 ,在相同的热处理条件下 ,对比研究了 840 7、4Cr5 Mo Si V1钢的纵横向热疲劳特性 ,观察分析了两种钢的热疲劳裂纹形貌及深度 ,并选择典型试样进行扫描电镜分析 .结果表明 ,840 7钢比4Cr5 Mo Si V1钢的碳化物...采用自约束热疲劳试验方法 ,在相同的热处理条件下 ,对比研究了 840 7、4Cr5 Mo Si V1钢的纵横向热疲劳特性 ,观察分析了两种钢的热疲劳裂纹形貌及深度 ,并选择典型试样进行扫描电镜分析 .结果表明 ,840 7钢比4Cr5 Mo Si V1钢的碳化物颗粒较小 ,而且分布均匀 ,从而表现出较好的热疲劳性能 ;尤其是 4Cr5 Mo Si V1钢的横纵向热疲劳性能差异较 840 7钢大 ,即 840 7钢的各向同性要优于 4Cr5 Mo Si V1钢 ,与两种钢的横纵向冲击韧性的比值相对应 .展开更多
A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue ...A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron （Cr of 15%） is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance （IFR） and impact wear resistance （IWR） of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron （Cr of 15%）. The main reasons are that （1） the stress in medium Cr-Si cast iron is released in the as-cast state; （2） the matrix is fine pearlite with better toughness and plasticity; （3） the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; （4） high silicon content im- proves the morphology of eutectic carbide; （5） there is no seeondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.展开更多
文摘采用自约束热疲劳试验方法 ,在相同的热处理条件下 ,对比研究了 840 7、4Cr5 Mo Si V1钢的纵横向热疲劳特性 ,观察分析了两种钢的热疲劳裂纹形貌及深度 ,并选择典型试样进行扫描电镜分析 .结果表明 ,840 7钢比4Cr5 Mo Si V1钢的碳化物颗粒较小 ,而且分布均匀 ,从而表现出较好的热疲劳性能 ;尤其是 4Cr5 Mo Si V1钢的横纵向热疲劳性能差异较 840 7钢大 ,即 840 7钢的各向同性要优于 4Cr5 Mo Si V1钢 ,与两种钢的横纵向冲击韧性的比值相对应 .
基金Item Sponsored by Foundation of China National Nonferrous Metals Industry Corporation(96-124)
文摘A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron （Cr of 15%） is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance （IFR） and impact wear resistance （IWR） of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron （Cr of 15%）. The main reasons are that （1） the stress in medium Cr-Si cast iron is released in the as-cast state; （2） the matrix is fine pearlite with better toughness and plasticity; （3） the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; （4） high silicon content im- proves the morphology of eutectic carbide; （5） there is no seeondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.
