球墨铸铁用布氏硬度计的不确定度评定

Evaluation of uncertainty of Brinell hardness for nodular cast iron

按照GB/T 231.1—2018《金属材料布氏硬度试验第1部分:试验方法》进行布氏硬度测试,分析影响测量结果的主要不确定度来源及分类,测试结果按照JJF 1059.1—2012 《测量不确定度评定与表示》进行不确定分析,并考虑扩展不确定度的测试分散性。结果表明:本实验室测试布氏硬度的不确定度为2HBW10/3 000,当包含因子为2时,扩展不确定度为(196±4)HBW10/3 000。同时在测试试件过程中,应避免测试人员长时检测所造成的视觉疲劳及试件的表面过热所引起的加工硬化现象。

Brinell hardness test was conducted according to GB/T 231.1-2018 Metallic materials-Brinell hardness test-Part 1:Test method.The main sources and sort of uncertainty,which influenced the measurement results,were analyzed.The uncertainty of measurement results was analyzed according to JJF 1059.1-2012 Evaluation and Expression of Uncertainty in Measurement.Meanwhile,the testing dispersion of expanded uncertainty was considered.The results showed that the uncertainty of Brinell hardness test in the laboratory was 2 HBW10/3 000.The expanded uncertainty was(196±4)HBW10/3 000 when the coverage factor was 2.At the same time,the visual fatigue caused by long-time inspection of operator and the work hardening caused by overheating of surface of test specimen should be avoided in the process of testing.