维氏硬度试验的测量不确定度评定

利用FW214自动维氏硬度计,通过综合评定法对经校准的459HV10标块进行试验;并对测量结果的影响因素进行了分析,进而评定了维氏硬度试验的测量不确定度。结果表明：该试验室检测方法、检验水平能够满足GB/T 4340.2要求;综合评定法在提高检验效率的同时也能满足试验准确度需求。     

维氏硬度计稳定性测试

利用数理统计的方法对实验室维氏硬度计稳定性进行测试和评价,根据每次试验结果的测量不确定度建立"测量不确定度随时间变化图",对其使用情况作出有效评价.结果表明:硬度计运行稳定,满足检验要求.但压痕自动测量功能测量的硬度值常比实际数值稍大,建议对硬度计进行检查,调整因设备硬件造成的误差,保证结果更准确.     

基于仪器化Vickers压入比功与马氏硬度识别材料维氏硬度的方法

针对传统维氏硬度测试中因Vickers压痕形貌不清晰导致的维氏硬度无法识别问题,应用量纲定理和有限元数值分析方法对仪器化Vickers压入响应进行了系统分析,同时,结合维氏硬度有限元数值计算结果,揭示仪器化Vickers压入比功、马氏硬度与维氏硬度的近似函数关系。基于上述关系,提出由Vickers压入比功We/Wt和马氏硬度HM识别材料维氏硬度HV的新方法,对该方法进行测试精度分析,验证结果表明该方法较ISO14577中所提维氏硬度仪器化Vickers压入方法具有更高的测试精度。     

A quantitative alternative to the Vickers hardness test based on a correlation between thermal diffusivity and hardness—applications to laser-hardened carburized steel

A quantitative non-destructive test technique for characterizing heat treated steel based on a theoretical model was developed and verified by experiments using the optical beam deflection technique at metallic samples, heated by a Gaussian beam. The analytic solution of the heat equation with appropriate approximations provides a theoretical expression of the surface temperature, which is an important guide to optimize the experimental process. Measurements have been focused on determining both, mechanical parameters and thermal local properties, in order to find correlations. The theoretically described thermal diffusivity was experimentally measured by using the new developed photo-thermal deflexion inversion procedure. A simple correlation between the micro-hardness according to Vickers and the thermal diffusivity was found for laser-hardened specimens depending on their microstructure and individual chemical composition.     

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 通过对金属维氏硬度试验的不确定度的分析与计算，介绍一种维氏硬度试验不确定度的评定方法。     

球墨铸铁用布氏硬度计的不确定度评定

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。     

球墨铸铁用布氏硬度计的不确定度评定

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2HBW10/3000,...     

Effect of annealing on the microstructures and Vickers hardness at room temperature of intermetallics in Mo-Si system

The microstructures and Vickers hardness at room tempcrature of arc-melting processed intermetallics of Mo5Si3-MoSi2 hypoeutectic alloy and hypereutectic alloy annealed at 1200℃ for different time were investigated. Lamellar structure consisted of MosSi3 (D8m) phase and MoSi2 (C11b) phase was observed in all the alloys. For Mo5Si3-MoSi2 hypoeutectic alloy, the lamellar structure was found only after annealing and developed well with fine spacing on the order of hundred nanometers after annealing at 1200℃ for 48 h. But when the annealing time was up to 96 h, the well-developed lamellar structure was destroyed. For Mo5Si3-MoSi2 hypereutectic alloy, the lamellar structure was found both before and after annealing. However the volume fraction and spacing of the lamellar structure did not change significantly before and after annealing. The effects of the formation, development and destruction of lamellar structure on Vickers hardness of alloys were also investigated. When Mo5Si3-MoSi2 hypoeutectic alloy annealed at 1200℃ for 48 h, the Vickers hardness was improved about 19% compared with that without annealing and formation of lamellar structure. The highest Vickers hardness of Mo5Si3-MoSi2 hypereutectic was increasing about 18% when annealing at 1200℃ for 48 h.