(1) contamination of impurity elements causes embrittlement
Titanium is an active element, especially in the welding high temperature is very easy to absorb nitrogen, hydrogen, oxygen, so that the weld hardness, strength, plasticity, toughness decreased, causing embrittlement. Carbon and titanium will form a hard and brittle TiC, easy to cause cracks. Therefore, UTI Titanium reminds you that titanium and titanium alloy welding must be effectively protected against air or other factors. So titanium and titanium welding can not be used gas welding or electrode arc welding method, otherwise the joints can not meet the welding quality requirements, generally only use argon protection or welding under vacuum.
(2) plastic deformation caused by welding phase change
Commonly used industrial titanium for the α alloy, aerospace titanium industry in the production and processing of more than 10 years to experience the welding due to titanium thermal conductivity, heat than the small, high temperature residence time, cooling speed, easy to form a large crystallization; Cooling, and easy to produce acicular α tissue, will also reduce the plastic.
(3) produce welding cracks
Titanium alloy welding heat generated when the probability of welding is very small, only when the quality of the wire or the base material is not a problem when it may produce hot cracks. The cold cracking caused by hydrogen should be avoided when the titanium alloy is welded, and the hydrogen in the molten pool and the low temperature zone is affected by the diffusion of hydrogen in the heat affected zone, resulting in the increase of the hydrogen content in the heat affected zone, resulting in delayed crack in the heat affected zone The
Titanium and titanium alloy welding hole is the most common welding defects. Welding wire or base material surface clean or argon impure can cause stomata, so the protection of gas - argon purity requirements in more than 99.99%, wire and the surface of the workpiece to pickling, rinse with water after drying.