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结合挖掘机实际生产工况，从材料动态断裂特性的研究入手，对国内两种斗杆用钢的使用情况进行了分析。结果表明：材料在动载下抗脆断能力的高低是决定斗杆寿命的重要因素。１５ＭｎＶ钢的韧－脆转变特征对加载速率十分敏感，在模拟挖掘机缓慢撞击大块岩石工况下，其韧－脆转变温度可由原先静载下的－４０℃升至该动载速率下的－１２℃。如果进一步提高加载速率到冲击试验状态，其韧－脆转变温度可升至２２℃以上。而ＨＱ８０钢对加载速率的敏感性较低，即使在冲击试验状态，其韧－脆转变温度仍可达－４０℃。这两种钢在动载特性方面的差异与斗杆在矿山实际使用寿命的差异情况相吻合。
Combined with the actual production conditions of excavators, starting with the study of dynamic fracture properties of materials, the use of two types of arm steel in China is analyzed. The results show that the material resistance to brittle fracture under dynamic load level is an important factor in determining the arm life. The tough-brittle transition characteristics of 15MnV steel are very sensitive to the loading rate. Under the conditions of slow-impacting large rock with a simulated excavator, the ductile-brittle transition temperature of the 15MnV steel increases from -40 ℃ to the dynamic loading rate -12 ° C. If you further increase the loading rate to the impact test state, the ductile-brittle transition temperature can rise above 22 ℃. However, the HQ80 steel is less susceptible to loading rate and its tough-brittle transition temperature can reach as high as -40 ° C even in impact test conditions. The difference between the dynamic characteristics of these two steels is consistent with the differences between sticks in actual service life of mines.