Measurement of Brinell Hardness of Thin-walled Tubes with Wall Thickness of 3 mm or Less

The measurement values of Brinell hardness of thin-walled tube with wall thickness of 3 mm or less were volatile.The Brinell hardness values in different depths from outer walls of thin-walled tube were obtained by hardness test.The metallographic examination results showed that there was obvious influence on Brinell hardness values by measurement depth, which was mainly caused by decarburized layer.