为了解决国内外冷轧薄钢板拉伸试验标准不统一,断后伸长率(A)受试样标距影响, 没有直接可比性及换算的局限性, 同时也为了满足车身设计人员提出的同一冲压级别的汽车板应采用同一种标准的伸长率表征力学性能的要求, 采用大量试验验证了最大力总伸长率(Agt)与试样标距无关。并根据拉伸试验机已能自动测出Agt的现状, 提出应将其列入汽车板标准力学性能表中。

To solve problems of the cold-rolled steel sheets such as the tensile testing standards are not unified in the international, the percentage elongation after fracture (A) is affected by the specimen gauge length creating no direct comparability and conversion limitations, also to meet the requests that the automobile steel sheets of the same stamping level should adopt the percentage elongation of the same standard reflecting mechanical properties proposed by automobile body designers, this article proved that there is no relationship between the percentage total elongation at maximum force (Agt) and the specimen gauge length by the test. According to the status quo that Agt can be measured by tensile testing machine, it was advanced that Agt should be included in the table of the mechanical properties for the standard of automobile steel sheets.