Al alloy (Al)/steel dissimilar metals structures have a critical application in the aerospace industry

especially in the delivery pipeline of high thrust liquid launch vehicles. Compared with welding methods such as fusion welding and brazing

rotary friction welding can achieve a reliable joint between Al and steel with high quality

high strength and high corrosion resistance. The research progress of rotary friction welding of Al/steel dissimilar metals was reviewed from the optimization of welding process parameters

analyses of interface microstructures

control of interface inhomogeneity and metallurgical control by adding inter-layer metals. Finally

the development trends and scientific problems to be solved in rotary friction welding of Al/steel dissimilar metals were summarized.