一、问题的提出小能量多次冲击接触疲劳抗力是衡量机械零件寿命的重要性能指标之一。对于一般机械零件所承受的小能量多次冲击来说,材料的冲击抗力主要取决于强度而不是韧性。凡能合理提高机械零件强度,保证一定塑性、韧性的措施都能有效地提高机械零件寿命。牙轮钻头是开发油田和矿山的重要工具,国内一般选用20CrMo 和20CrMoNi 钢经渗碳淬火处理。目前,国产钻头寿命还 First, the issue of small energy multiple impact exposure to fatigue resistance is one of the important performance indicators to measure the life of mechanical parts. The impact resistance of a material depends mainly on its strength, not on its toughness, for a small energy multiple impact on a typical mechanical part. Where a reasonable increase mechanical strength, to ensure a certain degree of plasticity, toughness measures can effectively improve the life of mechanical parts. Tricone bit is an important tool for the development of oil fields and mines, the domestic selection of 20CrMo and 20CrMoNi steel by carburizing quenching. At present, the domestic drill life also