HGCJ-20型棒材拉伸-冲击试样加工中心可实现冲击试样的一步加工成型，为保持冲击试样的对中性和固定性，需要在其一端钻顶针孔。通过对不同钻孔后的冲击标准试样以及42CrMo钢和Q235H钢的冲击加工试样进行冲击试验，对比研究了顶针孔及其深度对冲击试样冲击吸收能量测试值的影响以及采用HGCJ-20型棒材拉伸-冲击试样加工中心与传统加工工艺对冲击试样冲击吸收能量测试值的影响。结果表明：对于42CrMo钢和Q235H钢，采用新型加工中心加工的顶针孔深度为5 mm的冲击试样的冲击吸收能量实测平均值和采用传统工艺加工的冲击试样的一致；对于冲击标准试样和Q235H钢冲击加工试样，当冲击试样一端无顶针孔或顶针孔深度不大于8 mm时，冲击试样的冲击吸收能量实测平均值较稳定，在正常范围（110~120 J）波动；当顶针孔深度达到9 mm并高于该数值时，冲击试样冲击吸收能量实测平均值普遍低于正常范围。

HGCJ-20 bar tensile impact specimen machining center can realize one-step processing and forming of impact specimen. In order to maintain the neutrality and fixity of impact specimen, it is necessary to drill a pin hole at one end of it. Through the impact test of the impact standard specimens and the impact processing specimens of 42CrMo steel and Q235H steel after different drilling, the influence of the pin hole and its depth on the impact absorption energy test value of the impact specimens and the influence of HGCJ-20 bar tensile impact specimen processing center and traditional processing technology on the impact absorption energy test value of the impact specimens were compared. The results show that for 42CrMo steel and Q235H steel, the average value of the impact absorption energy of the impact specimens processed by the new machining center with the pin hole depth of 5 mm was the same as that of the impact specimens processed by the traditional technology. For the impact standard specimen and Q235H steel, when there was no pin hole at one end of the impact specimen or the depth of the pin hole was not more than 8 mm, the measured average value of impact absorption energy was stable and fluctuated in the normal range (110-120 J). When the depth of the pin hole reached 9 mm and was higher than this value, the measured average value of impact absorption energy of the impact specimen was generally lower than the normal range.