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

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.