Effect of Heat Input on Tin Bronze-Induced Intergranular Cracks During Arc Cladding Process

This work aimed to figure out the effect of heat input on the characteristics, formation, and elimination of liquid tin bronze-induced intergranular cracks in steel sheets with a thickness of 2 mm. Tin bronze cladding layers were prepared using an arc cladding technique on the steel. A statistical method was adopted to analyze the severity of intergranular cracks. Microstructures and intergranular cracks were characterized by SEM and TEM. The tensile experiments were carried out using an electronic universal testing machine. For the bare steel sheets, the intergranular cracks originated from the cladding layer and propagated into the interior of the steel along the grain boundaries. The intergranular cracks could evolve into macrocracks and lead to the failure of steel. With the increase in heat input, the maximum temperature, maximum stress, and contact time between steel and liquid tin bronze increased. The severity of intergranular cracks was also increased, and the longest crack reached 520 μm. The mechanical properties of the steel sheets decreased with the increase in heat input. For nickel-plated steel sheets, intergranular cracks were eliminated under low heat input, and a transition layer with a nickel content of 12.32 wt.% was generated. The intergranular cracks generated under high heat input and nickel content in the transition layer were only 1.34 wt.%. The strength of the nickel-plated steel also decreased drastically, and the ductility was almost zero.