摘要
对发生断裂的载重汽车用轮轴的化学成分、宏观形貌、力学性能、断口形貌、显微组织等进行了检测与分析。结果表明,载重汽车用轮轴的化学成分符合标准JIS G 4051—2005中对S55C钢的要求,材料强度满足标准规定的技术要求,但断后伸长率总体低于技术要求,断后伸长率比技术要求下限低33%以上,载重汽车用轮轴金相组织为网状铁素体和珠光体,轮轴的韧塑性较差,使得在受到冲击应力作用时发生脆性断裂。
Taking the axle used for heavy truck as an object, it analyzes the chemical composition, macroscopic appearance, mechanical properties, fracture morphology and microstructure. The results show that the chemical composition of the wheel axle of the truck meets the requirements for S55C steel in the standard JIS G 4051—2005, and the strength of the material meets the technical requirements stipulated in the standard, but the elongation is lower than the technical requirement, and the elongation is 33% lower than that of the technical requirement. The matrix structure of the wheel axle is large pearlite and reticular ferrite, its toughness and plasticity are lower, and the microstructure at surface layer is martensitic by hardening treatment, and the toughness and plasticity of the material descend further. The fracture of the axle presents the shape of inter-granular and cleavage brittle fracture, a certain impact stress and poor toughness of the material cause the brittle fracture of the axle.
引文
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