Effects of preheating temperature on cold cracks, microstructures and properties of high power laser hybrid welded 10Ni3CrMoV steel

► A Y-groove cold cracking test is designed to assess the laser hybrid welded joints. ► As preheating temperature increases, the crack rate decreases and then increases. ► Thermal cycles of different preheating temperatures illustrate crack resistance. ► The preheating temperature changes the microstructures of laser welded joints.