Study on Bonding Properties of Different Surfacing Layer Metals with 45 Steel Base Metal

Austenite steel, Nb-bearing alloy steel, and high-Cr alloy cast iron surfacing layers (SL) were grown on 45 steel base metal (SBM) by using the arc surfacing method with self-shielded flux-cored welding wire and fusion electrode, and the composition and microstructure of these SLs were analyzed. The criss-cross push-off (CCPO) specimens for each type were processed, and the bonding property between SLs and 45 SBM was measured using a customized CCPO test. The fracture path and fractograph characteristics were also investigated using a metallographic and scanning electron microscope. The experimental results indicated that the bonding strength (BS) of austenite steel SLs and 45 SBM was the highest (465 MPa); the fracturing sites were near the fusion line, and the fracture exhibited cleavage fracturing features. The BS of niobium-bearing alloy steel and 45 SBM was 310 MPa, and the fracture was at the bottom of the SLs and exhibited quasi-cleavage fracturing features. The BS of the alloy cast iron SLs and 45 SBM was 175 MPa, and the fracture was at the bottom of the SLs and showed brittle fracturing features.