【摘要】 为探究某液压支架立柱柱头失效原因，采用宏观检验、化学成分分析、金相组织检验、扫描电镜等手段对断口形貌进行分析。结果表明：裂纹起源于柱头心部，后成斜面向四围延伸，起始端宽大，末端细尖，具有典型淬火裂纹特征；立柱柱头的化学成分符合要求，出现淬火裂纹的主要原因为原材料存在非金属夹杂物；热处理工艺冷速不当，导致立柱在介质中冷却时速度有差异，使柱头中部位置产生较大拉应力；金相分析可见沿晶+穿晶裂纹，断口可见蜂窝状凹坑，断口形貌伴随明显的河流状花样和夹杂物颗粒，其断口失效的表现形式主要是脆性、韧性混合断裂机制。上述因素共同导致30CrMnSi钢立柱柱头产生裂纹进而失效。更多还原

【Abstract】 In order to explore the cause of the failure of a hydraulic support column head, macroscopic inspection, chemical composition analysis, metallographic structure inspection, and scanning electron microscopy were used to analyze the fracture morphology. The results showed that the crack originated from the center of the column head and extended diagonally around it, with a wide starting end and a fine pointed end, exhibiting the typical characteristics of a quench cracks. The chemical composition of the column head meets the requirements, and the main reason for quench cracks is the presence of non-metallic inclusions in the raw material. The improper cooling rate of the heat treatment process results in differences in the cooling speed of the column in the medium, causing greater tensile stress in the middle of the column head. Metallographic analysis reveals intergranular and transgranular cracks,with honeycomb like pits visible on the fracture surface, the fracture morphology is accompanied by obvious river like patterns and inclusion particles, the main manifestation of fracture failure is a brittle ductile mixed fracture mechanism. The above factors collectively led to the cracking and failure of the 30 CrMnSi steel column head.更多还原