Influence of chromium content on the bainite transformation nucleation mechanism and the properties of 800 MPa grade low carbon bainite weld deposited metal

The strength-toughness trade-off theory is always the focus in field of high-strength structure materials. Especially for deposited metals, matching and accepted toughness difficult to achieve. In this work, nucleation mechanism bainite ferrite (BF) impact were investigated systematically metals with different chromium (Cr) contents (0.3 wt %, 0.6 % 1.0 %). microstructure Cr was analyzed by a combination multiple analytical tools: scanning electron microscope, transmission microscope backscatter diffraction. results revealed that autocatalytic during transformation had significant effect on evolution due complex crystallographic orientation BF. As content increased, became weaker, selection tendency variants enhanced. primarily controlled kinetics Enough space at side existing BF resulted from low speed necessary occurrence nucleation. addition, decreased as weakened coarsening appearance coalesced metal. interlaced arrangement could bring better high strength metals. • An carbon metal has achieved an excellent toughness. been explained detail. successfully characterized. formation carefully.