Mechanical property improvement of wire-arc additive manufactured 06Cr19Ni9 steel based on ultrasonic strengthening grinding process

Wire-arc additive manufacturing (WAAM) technology offers an effective approach to fabricating complex metallic components. However, the existing WAAM process is limited in producing a metallic component with high mechanical strength. In this study, the ultrasonic strengthening grinding process (USGP) was proposed to enhance the mechanical properties of WAAM-processed 06Cr19Ni9 steel. A multiphase abrasive, comprising zirconia ceramic balls, brown corundum powder, and strengthening liquid, was propelled by an ultrasonic vibration and randomly impacted on the surface of the WAAM-processed sample. Subsequently, a uniaxial tensile test was conducted to evaluate its mechanical properties. The evolutions of microhardness, microstructure, and phase transformation were comprehensively analyzed. The results revealed that UGSP treatment promotes the generation of dendritic grains and dislocations, facilitates phase transitions, and augments stacking fault and twin band sizes. These cumulative effects enhanced the tensile properties of 06Cr19Ni9 steel. The resulted yield strength and tensile strength achieves a value of ∼970 MPa and ∼1032 MPa, respectively, which increased by ∼43.73% and ∼95.96% compared to the untreated sample. The finding suggested that the proposed method has great application prospects in improving mechanical properties of WAAM-processed components and has the advantages of high efficiency, low cost, and small equipment size.