Abstract In this paper Small Punch Tests (SPT) are used to determine the mechanical properties of the heat affected zone (HAZ) of CrMoV welded joints and to evaluate the embrittlement caused by the presence of internal hydrogen. Hydrogen permeation tests were carried out to determine the effective diffusion coefficients of the different regions of welded joints, whose hydrogen contents were measured using a hydrogen analyser. The paper demonstrates that SPTs can be used to estimate the tensile properties and the toughness of small areas, such as the subzones of a welded joint which are not thick enough for machining standard specimens. In cases where it is not possible to determine the fracture toughness of brittle regions using standard SPT samples, tests using longitudinally notched SPT samples were conducted. The normalized energy at failure, W / t 2 , was selected as the most appropriate SPT parameter to estimate the fracture toughness regardless of the fracture behaviour of the material (ductile or brittle). It was seen that the fracture toughness of the fine grained HAZ (FG-HAZ) is similar to that of the Base Metal (BM), while the fracture toughness of the coarse grained HAZ (CG-HAZ) is more similar to that of the Weld Metal (WM). The effect of hydrogen on BM and FG-HAZ is low, with embrittlement indexes of about 20%. However, a strong effect of hydrogen was observed in CG-HAZs and WMs, with embrittlement indexes of 60–80%. and a clear change from ductile to brittle behaviour in their fracture surfaces.

中文翻译：

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CrMoV焊缝氢脆的SPT分析

摘要 在本文中，小冲孔试验(SPT) 用于确定CrMoV 焊接接头热影响区(HAZ) 的机械性能，并评估由内部氢的存在引起的脆化。进行氢渗透试验以确定焊接接头不同区域的有效扩散系数，使用氢分析仪测量其氢含量。该论文表明，SPT 可用于估计小区域的拉伸性能和韧性，例如焊接接头的子区域，这些区域的厚度不足以加工标准试样。如果使用标准 SPT 样品无法确定脆性区域的断裂韧性，则使用纵向缺口 SPT 样品进行测试。故障时的归一化能量，W / t 2 被选为最合适的 SPT 参数来估计断裂韧性，而不管材料的断裂行为（延展性或脆性）。可以看出，细晶粒热影响区 (FG-HAZ) 的断裂韧性与母材 (BM) 的断裂韧性相似，而粗晶粒热影响区 (CG-HAZ) 的断裂韧性更类似于母材 (BM) 的断裂韧性。焊接金属 (WM)。氢对BM和FG-HAZ的影响较小，脆化指数约为20%。然而，在 CG-HAZs 和 WMs 中观察到氢的强烈影响，脆化指数为 60-80%。以及它们的断裂表面从韧性到脆性的明显变化。可以看出，细晶粒热影响区 (FG-HAZ) 的断裂韧性与母材 (BM) 的断裂韧性相似，而粗晶粒热影响区 (CG-HAZ) 的断裂韧性更类似于母材 (BM) 的断裂韧性。焊接金属 (WM)。氢对BM和FG-HAZ的影响较小，脆化指数约为20%。然而，在 CG-HAZs 和 WMs 中观察到氢的强烈影响，脆化指数为 60-80%。以及它们的断裂表面从韧性到脆性的明显变化。可以看出，细晶粒热影响区 (FG-HAZ) 的断裂韧性与母材 (BM) 的断裂韧性相似，而粗晶粒热影响区 (CG-HAZ) 的断裂韧性更类似于母材 (BM) 的断裂韧性。焊接金属 (WM)。氢对BM和FG-HAZ的影响较小，脆化指数约为20%。然而，在 CG-HAZs 和 WMs 中观察到氢的强烈影响，脆化指数为 60-80%。以及它们的断裂表面从韧性到脆性的明显变化。在 CG-HAZs 和 WMs 中观察到氢的强烈影响，脆化指数为 60-80%。以及它们的断裂表面从韧性到脆性的明显变化。在 CG-HAZs 和 WMs 中观察到氢的强烈影响，脆化指数为 60-80%。以及它们的断裂表面从韧性到脆性的明显变化。