Friction spot joining (FSJ) was applied to DP590 steel using an uncoated Si3N4 tool without using shielding gases. The microstructural distribution and microstructural evolution of the steel were systematically examined. A defect-free joint exhibited a heterogeneous microstructural distribution, which could be explained mainly by the phase transformation at different peak temperatures during joining. Further, an elliptical region near the pinhole was contaminated by oxygen, silicon, and nitrogen. These contaminants strongly affected the microstructural evolution of the joint.
|Number of pages||3|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 2009|