核电用316H不锈钢板蠕变性能测试影响因素探讨

Discussion about influencing factors in creep test of 316H stainless steel plate for nuclear power

火电站和核电站装备用钢的升级换代对耐热钢高温服役性能评价提出了更高的要求。因此,准确、可靠的蠕变试验数据显得尤为重要。以核电用316H不锈钢板为研究对象,通过一系列高温蠕变试验探讨了取样位置、试样尺寸、设备差异对蠕变性能测试结果的影响。受生产工艺影响,该316H不锈钢板中部(1/2位置)材料与表层(1/4位置或3/4位置)材料的抗蠕变性能差异显著,中部位置材料的总伸长率比上部材料低44%,表明取样位置会对不锈钢板蠕变性能测试结果产生较大影响;平行段直径为?10 mm的试样与平行段直径为?5 mm的试样的蠕变性能测试结果差异较小,总伸长率相差约11%,表明试样尺寸对不锈钢板蠕变性能测试结果产生的影响较小;受设备差异影响,相同取样位置、试样尺寸的试样的蠕变性能测试结果差异较小,30台蠕变试验机测试的总伸长率的相对标准偏差约9.5%,表明设备差异对不锈钢板蠕变性能测试结果产生的影响较小,当设备校准合格时可以忽略设备差异对蠕变性能测试结果的影响。

The upgrading of steel for thermal power plant and nuclear power plant equipment puts forward higher requirements for the evaluation of high-temperature service performance of heat-resistant steel.Therefore,the accurate and reliable data in creep test are particularly important.In this study,316H stainless steel plate for nuclear power was selected as the research object.The influence of sampling position,sampling size and equipment difference on creep test results was discussed through a series of high temperature creep tests.Affected by the production process,the creep resistance of the material in the middle(1/2 position) of the 316H stainless steel plate was significantly different from that in the surface(1/4 position or 3/4 position),and the total creep strain of the material in the middle was 44% lower than that of the upper material,indicating that the sampling position had a great impact on the creep test results of stainless-steel plate.The creep test results of the sample with parallel section diameter of 10 mm and the sample with parallel section diameter of 5 mm had little difference,and the total creep strain difference was about 11%,indicating that the specimen size had little influence on the creep test results.Affected by the equipment difference,the creep test results of samples with the same sampling position and specimen size had little difference.The relative standard deviation of the total creep strain tested by 30 creep testing machines was about 9.5%,indicating that the equipment difference had little impact on the creep test results of stainless-steel plates.When the equipment calibration was qualified,the influence of the equipment difference on the creep test results could be ignored.