摘要
夏比(Charpy)冲击试验是评价冲击载荷下材料塑性变形和断裂过程中吸收能量的能力的试验方法。虽然试验中测定的冲击吸收功Ak值不能作为表征金属制件实际抵抗冲击载荷能力的韧性判据,但是因为其试样加工简便,试验时间短,实验数据对材料组织结构、冶金缺陷等敏感,因而成为评价金属材料冲击韧性的一种传统力学性能试验方法,被世界各国广泛采用。不同国家的冲击试验标准对试验机、试样、试验程序和试验结果的处理与修约的规定不尽相同,对日本的JIS标准、美国的ASTM标准和中国的GB标准中关于钢产品的冲击试验规定进行比较,列举了它们之间的差异并对这些差异对试验结果的影响进行讨论。由于均源自ISO148,中国和日本的冲击试验标准对冲击试验机及其附件、冲击试样、冲击试验程序和冲击试验结果处理与修约的规定基本一致,只是日本标准对试样部分尺寸的允许偏差要求较中国严格。与日本和中国的标准相比,ASTM标准在试验机及其附件、试验程序、试样和试验结果处理与修约方面的规定存在较大差异。ASTM使用刀刃曲率半径8 mm的摆锤,同一组试样得到的冲击吸收功可能与中国标准存在差异。对试验温度的控制要求更严格,分别为规定温度的±2℃和±1℃。冲击试样取样位置和对冲击试样方向的定义也不完全相同。ASTM标准对试样尺寸的允许偏差更严格,缺口角度分别为45±2°和45±1°、缺口深度分别为2±0.15 mm和2±0.025 mm以及相邻面角度分别为90±2°和90±0.167°;由此引起的冲击吸收功变化也较小。ASTM标准的试验结果处理与修约方面与中国标准也有较大区别。
Charpy impact test is a test method for evaluating the energy absorbing ability of materials during plastic deformation and fracture under impact load. Although the absorbed energy value Aa obtained in impact test can not characterize resistance to impact load of steel products, it is widely used in the world since the easy manufacturing of its specimen, the less time consuming of it and the sensitivity of its result to structure and metallurgical defects of materials. Requirements of different countries＇ Charpy impact standards are not the same in impact machines, impact specimens, test procedures and rounding methods of test results. Impact test standards for steel products of Japan, America and China are compared, the differences between them are listed and the influences of the differences on the test result are discussed. The standards of Japan and China are almost the same because they both are originated from ISO 148. However, ASTM Charpy impact test standards are different from the JIS and GB standards.
出处
《物理测试》
CAS
2009年第4期37-42,共6页
Physics Examination and Testing
