【摘要】 用硬度法及金相法分析了20MnV钢圆环链的内在质量，发现淬硬层过度回火和心部“平衡组织（F＋P＋B）区”过大是导致圆环链强度储备不足，在使用中被拉长的主要原因。适当增加淬火温度，降低回火温度并设法增加淬火介质的冷却能力是提高其强度储备，防止使用中拉长的主要途径。更多还原

【Abstract】 The quality of 20MnV steel ring chains was analysed by means of hardness and microscopic analyses.It was denoted that the quenching’layer over tempered and the "equilibrium structura1 area (F+P+B)"too more were the main reasons of strength reserve too small and the chains changed 1onger during working- 1t was main technology means of increasing strength reserve and preventing chains changed longer during woFking that in creasing quenching temperature,reducing tempering temperature and increasing the cooling ability of quenching medium.更多还原