便携磁力式布氏硬度计在薄壁小径管硬度检验中的实用性

Practicability of Portable Magnetic Brinell Hardness Tester in Hardness Test of Thin-Walled Small-Diameter Tubes

以电厂薄壁小径管为研究对象,采用便携磁力式布氏硬度计对其进行硬度测试,然后分别使用简易目镜、压痕自动测量系统和数显布洛维硬度计所配备的目镜测量压痕直径,并将3种测量方法的硬度试验结果与数显布洛维硬度计的试验结果进行了对比,以研究便携磁力式布氏硬度计在薄壁小径管硬度检验中的实用性。结果表明:便携磁力式布氏硬度计试验后采用不同方法进行压痕直径测量时,压痕自动测量系统受试验管材打磨面不平整度的影响,其试验结果往往高于数显布洛维硬度计的,而简易目镜和布洛维目镜测量的试验结果与数显布洛维硬度计的相比误差很小;高合金薄壁小径管进行硬度试验时,在不影响管材使用性能的情况下需尽可能将试验面打磨平整光滑,以减小试验误差。

With the thin-walled small-diameter tubes in power plants as the research object,firstly the hardness test was carried out with portable magnetic Brinell hardness tester,and then the indentation diameters were measured by simple eyepiece,indentation automatic measurement system and the eyepiece equipped on the digital universal hardness tester respectively.And the hardness test results of these three kinds of measurement methods were compared with the test results of digital universal hardness tester to study the practicability of portable magnetic Brinell hardness tester in hardness test of thin-walled small-diameter tubes.The results show that after hardness test with portable Brinell hardness tester,if the indentation diameters were measured by indentation automatic measuring system,the test results were often higher than those tested with digital universal hardness tester for the effect of unevenness of the test tube polished surface.If the indentation diameters were measured by simple eyepiece or the eyepiece equipped on the digital universal hardness tester,the test error compared to the test results of digital universal hardness tester was rather small.When testing the hardness of high alloy small-diameter tubes,the inspection surface should be polished as flat and smooth as possible in the premise of non-affecting the service performance of the tubes,so as to reduce the test error.