引言在进行高强度合金钢材、有色合金以及球墨铸铁等金属材料的机械性能常规测试时,针对这些材料没有明显抗拉屈服点σ_S的特点,国家标准金属抗力试验法指明,应测定其屈服限σ_(0.2),即试样抗拉残余伸长等于原标距长度0.2％时的屈服限。在普通全能拉力试验机上进行这项测试工作时,一般采用引伸计法 Introduction In the routine testing of the mechanical properties of high strength alloy steel, non-ferrous alloy and ductile iron and other metal materials, there is no obvious yield point σ_S for these materials. The national standard metal resistance test method indicates that the yield limit σ_ (0.2), that is, the specimen tensile residual elongation equal to 0.2% of the original gauge length when the yield limit. In the general all-purpose tensile testing machine for this test work, the general use of extensometer method