Here is a professional Titanium Alloy Plate Exporter talking about the
countermeasures to solve the cracks produced in titanium sheet.
Cracks are a frequent defect in the welding of Titanium Sheet. Titanium weld cracks are cold cracks and are mainly caused by hydrogen in the weld. The source of hydrogen is mainly the moisture and oil in the plate and the welding wire. The environmental humidity is the main reason for the hydrogen increase in the weld.
Under the action of high temperature during welding, a large amount of hydrogen is dissolved in the molten pool. During the cooling and solidification of the weld, hydrogen is easily escaping due to the rapid decrease of solubility. If the weld is cooled too fast, hydrogen will not escape and remain in the weld, which will cause the hydrogen in the weld to be supersaturated, so the hydrogen will spread as much as possible and promote further embrittlement in this area.
If there is a notch effect in this part and the concentration of hydrogen is sufficiently high, cracks may occur. Especially in winter construction, the ambient temperature is low, and water vapor adheres to the titanium plate, which creates conditions for hydrogenation in the weld. Since the titanium plate is too thin (1.2mm), the steel plate is relatively "eat temperature", the temperature rises slowly, and the corresponding titanium composite layer welds are cooled too fast. During the cooling process, the residual hydrogen in the weld is too late to escape. Exist in the form of supersaturation in the weld, eventually leading to the appearance of cracks.
Therefore, in the welding process of titanium steel composite plates, the surface of the base metal and the welding wire should be carefully cleaned to keep the ambient temperature not lower than 5 °C. In winter construction, the flame is used to preheat the base steel surface, one is to remove the moisture around the weld; the other is to increase the temperature of the amendment and reduce the cooling speed of the weld.