Super duplex stainless steels (SDSS) are used in offshore applications and oil/gas plants operating under severe service conditions due to their superior mechanical and electrochemical properties. Fracture toughness, wear and corrosion resistance of a material depends largely on its microstructure and can be improved by refining the latter. Friction stir processing (FSP) can be employed to refine the microstructure of the material, resulting in superior fracture toughness, wear, and corrosion resistance. In the present research, SAF 2507 SDSS was subjected to FSP with optimized processing parameters to study the influence of FSP on fracture toughness, wear, and corrosion resistance of the material. It was observed that FSP refined alloy grains by decreasing the grain size from an average of 160 µm in the base metal to 2-30 µm in the stir zone. Refinement of grains increased the hardness of the material, which enhanced its wear resistance by more than 15%. Wear track and debris analysis revealed the change in wear mechanism of the processed material. FSP also modified the surface composition of processed material, which served to improve its corrosion resistance by more than 80%. Morphology of the corroded surfaces of base and processed material showed that the processed material was more resistant to corrosive attacks than base material. FSP enhanced the grain boundaries in the processed region which improved the fracture toughness after exposure to accelerated corrosion by about 26%. Fractographic study revealed that processed material had brittle fracture behavior while base material had ductile fracture behavior.

超级双相不锈钢（SDSS）由于其优越的机械和电化学性能而用于海上应用和在严苛服务条件下运行的石油/天然气工厂。材料的断裂韧性，耐磨性和耐腐蚀性在很大程度上取决于其微观结构，可以通过对其进行细化来改善。可以采用摩擦搅拌工艺（FSP）来改善材料的微观结构，从而获得优异的断裂韧性，耐磨性和耐腐蚀性。在本研究中，对SAF 2507 SDSS进行了FSP优化工艺参数研究，以研究FSP对材料的断裂韧性，磨损和耐蚀性的影响。可以观察到，FSP通过将晶粒尺寸从贱金属中的平均160 µm减小到搅拌区的2-30 µm来细化合金晶粒。细化晶粒提高了材料的硬度，使材料的耐磨性提高了15％以上。磨损轨迹和碎片分析揭示了加工材料的磨损机理的变化。FSP还修改了加工材料的表面成分，从而将其耐腐蚀性提高了80％以上。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。使其耐磨性提高了15％以上。磨损轨迹和碎片分析揭示了加工材料的磨损机理的变化。FSP还修改了加工材料的表面成分，从而将其耐腐蚀性提高了80％以上。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。使其耐磨性提高了15％以上。磨损轨迹和碎片分析揭示了加工材料的磨损机理的变化。FSP还修改了加工材料的表面成分，从而将其耐腐蚀性提高了80％以上。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。FSP还修改了加工材料的表面成分，从而将其耐腐蚀性提高了80％以上。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。FSP还修改了加工材料的表面成分，从而将其耐腐蚀性提高了80％以上。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。基材和加工材料腐蚀表面的形态表明，加工后的材料比基材更耐腐蚀。FSP增强了加工区域的晶界，使加速腐蚀后的断裂韧性提高了约26％。分形研究表明，加工后的材料具有脆性断裂行为，而基体材料则具有韧性断裂行为。