14Cr17Ni2不锈钢锥形螺栓断裂分析
Fracture analysis of 14Cr17Ni2 stainless steel conical bolt
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摘要: 某锥形螺栓在摇动时发生断裂,通过对断口进行宏观和微观观察,可知螺栓的断裂性质为沿晶脆断.根据金相组织和维氏硬度检测结果,判断该螺栓硬度偏硬与其组织中无铁素体有关,结合其能谱成分、断裂性质以及回火温度情况,推断该螺栓可能存在回火脆性,最终通过人为打断在570℃回火有铁素体和无铁素体的14Cr17Ni2不锈钢试样,证明无铁素体的试样在570℃回火后脆性更大,断口为沿晶脆断,而有铁素体的试样断口则以准解理为主,确定了锥形螺栓的断裂是因回火温度处于回火脆性区间及组织中无铁素体相互作用而产生的.Abstract: A conical bolt broke during shaking.The fracture property of the bolt belongs to intergranular brittle fracture through the macroscopic and microscopic observations of the fracture surface.Based on the metallographic structure and Vickers hardness test results,it is determined that the hardness of the bolt is related to the absence of ferrite in its structure.Combining its energy spectrum,fracture properties,and tempering temperature,Infer that the bolt may have temper embrittlement.It is proved that the sample without ferrite has greater brittleness after tempering at 570℃,and the fracture surface is intergranular brittle fracture by artificially breaking the 14Cr17Ni2 stainless steel sample with and without ferrite tempered at 570℃,the fracture surface of the sample with ferrite is mainly quasi cleavage.Finally confirmed the fracture cause of the conical bolt was due to the interaction of the tempering temperature being in the tempering brittleness range and no ferrite in the structure.