中文摘要：

利用研究室自主研发的电弧微铸轧复合增材制造系统,无模直接成形出熔铸成形性和可焊性极低的45钢大壁厚差高强度零件,并在自由熔积和微铸轧复合两种工艺条件下进行对比试验,分析测试了45钢试样的组织特征和力学性能。结果表明：与自由熔积成形相比,微铸轧复合工艺将晶粒粒度由5.5级细化至12.0级,抗拉强度提高31.3%,屈服强度提高68.8%,平均硬度提高10.9%;与熔模铸造相比,微铸轧复合工艺将抗拉强度提高58.4%,屈服强度提高107.7%。因此,微铸轧复合增材制造技术将为难成形加工材料高强韧金属零件的低成本优质短流程制造提供一条有效途径。

英文摘要：

A new hybrid arc deposition- micro rolling additive manufacturing method was used to directly fabricate high strength 45 steel parts which has different thickness and low formability. In order to research the different process characters between free deposition and weld-rolling, the microstructure characteristics and mechanical properties of 45 steel specimens were tested. The results show that the weld-rolling technology can enhance the grain size level from 5.5 to 12.0, and the tensile strength, yield strength and hardness increase by 31.3% 、68.8% 、10.9%, respectively. Moreover, compared with investment casting, the tensile strength and yield strength increases by 58.4% 、107.7%, respectively. Therefore, weld-rolling hybrid additive manufacture process would provide a low cost, high quality and effective way to directly fabricate high toughness complex components.