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依据自强化中锰铸钢的成分设计原则和激光熔覆技术的工艺特点,研制了自熔剂型铁基自强化合金粉末。应用SEM、XRD和线接触疲劳试验(CF)研究了激光熔覆层的组织、结构及接触疲劳性能。研究表明:自熔剂型铁基自强化粉末的激光熔覆层与基体间的结合为冶金结合,组织为呈树枝状分布的奥氏体+弥散分布的粒状渗碳体;在2170MPa接触应力、12.5%滑差、20号机油润滑条件下,激光熔覆层的特征寿命为7.21×106周次,比相同条件下的渗碳层特征寿命6.29×106周次提高了15%,其原因是该熔覆层在接触应力作用下,具有应变诱发马氏体相变强化的特征。该技术适合于重载车辆传动渗碳齿轮的修复。
According to the composition design principle of self-strengthening medium-manganese steel and laser cladding technology, self-fluxing iron-based self-strengthened alloy powder was developed. The microstructure, structure and contact fatigue properties of the laser cladding layer were investigated by SEM, XRD and linear contact fatigue test (CF). The results show that the combination of the laser cladding layer and the matrix of the self-fluxing iron-based self-reinforced powder is metallurgical bonding, and the structure is granular cementite with dendritic distribution + dispersed distribution; at the contact stress of 2170MPa, % Slip, the characteristic life of the laser cladding layer is 7.21 × 106 cycles under the condition of 20 # oil lubrication, which is 15% higher than the 6.29 × 106 cycles of the characteristic life of carburized layer under the same conditions, Under the action of contact stress, the coating has the characteristics of strain-induced martensitic transformation strengthening. The technology is suitable for heavy-duty vehicle transmission carburized gear repair.