金属材料维氏硬度试验测量不确定度的评定

摘要

金属材料维氏硬度试验的测量不确定度主要来源于试验力、标准硬度块、压痕对角线长度的测量以及硬度计本身、试验结果的数值修约等.根据GB/T 4340.1-2009对硬度计和标准硬度块的要求,结合生产实际,计算了不同试验力下维氏硬度试验的测量不确定度.结果表明:硬度计的最大允许误差引起的测量不确定度所占的权重最大;对于同一维氏硬度,试验力越大,维氏硬度试验的测量不确定度则越小,因此在日常检测中,在满足要求的情况下,应尽可能选择较大的试验力,减小测量不确定度,使试验结果更加准确可靠.%The measurement uncertainty of metal material Vickers hardness test mainly results from test force, standard hardness block, measurement of indentation diagonal length, hardness tester itself, test result rounding off, etc.According to the requirements for hardness testers and standard hardness blocks in GB/T 4340.1-2009, combined with the production practice, the measurement uncertainty of Vickers hardness test with several different test forces was calculated.The results show that the measurement uncertainty derived from the maximum permissible error of the hardness tester was the largest.For the same Vickers hardness, the larger the test force was, the smaller measurement uncertainty of Vickers hardness test was.Therefore, in daily testing, under the premise of meeting the requirements, the test force should be chosen as large as possible to reduce the measurement uncertainty and make the test results more accurate and reliable.