Influence of brazing time on performance of row saw

CT643 brazfing filler was used to conduct welding experiments on row saw through high frequency brazing. The effect of brazing time on the performance of row saw was studied. The shear strength and morphology of the brazed joint were tested by universal capability testing machine and electron microscope. The brazing area of the solder beside the steel matrix was measured by body microscope. The microstructure and hardness of the heat affected zone were compared and analyzed by metallographic microscope and Rockwell hardness tester. The results show that with the increase of brazing time, the shear strength of joints decreases gradually, and the grain size at the heat affected zone grows to form tempered troostite. In addition, the brazing area of steel matrix decreases, and the area of heat affected zone increases with decreased hardness. When the brazing time was 1.8 s, the CT643 solder infiltrates into the steel matrix for about 90 μm, while the steel matrix diffuses to the solder interface to form bamboo shoot-like protrusions with a height of about 10 μm.