材料期刊网

在凸轮形变机上进行了G 3、1Crl3钢、铝及铅的恒应变率均匀压缩试验.试验温度:G 3及1Cr 13钢为1000℃,1100℃及1200℃,铝及铂则为室温.应变率共分五种,最低为12.2秒~(-1),最高为183秒~(-1).最大压缩率为56%;对于铅,最大會压缩到76%.准确地控制了试验温度,改进了消除试样端面摩擦的方法,获得了近于均匀压缩变形的条件,得出了对应于上述条件的真应力应变曲线.结果表明:在上述条件的范围内,G3、1Cr13铜及铅的应变率与变形抗力的关系符合于速度的指数公式(?)=(?),而铝的常温压缩真应力应变曲线则几乎与应变率无关.文中曾把试验结果与前人结果进行比较和讨论.

Homogeneous compression tests were carried out in a cam plastometer on mild steel,13% chromium steel,aluminium and lead.Aluminium and lead were tested at roomtemperatures;while mild steel and 13% chromium steel were tested at 1000,1100 and1200℃.Altogether five different rates of strain were used,ranging from 12.2 sec.~(-1)to 183 sec.~(-1),the rate of strain being kept constant during the test.With the exceptionof lead,which reached a reduction of 76%,the maximum reduction in height was 56%.During the tests,the testing temperatures were controlled accurately.The friction be-tween the specimen and the compression platens was successfully eliminated,so that testswere carried out under homogeneous compression conditions,and the true stress-straincurves corresponding to the above testing conditions were thus obtained.The experimental results show that under the above testing conditions the relation-ship between the rate of strain and the resistance to deformation for mild steel,13%chromium steel and lead obeys the following law(?)while the stress-strain curves for aluminium is practically unaffected by the change in theabove rates of strain.These experimental results have been discussed and compared withprevious work found in literature.