Welding process and method of titanium alloy plate
Titanium and titanium alloy have good weldability as common metals, but titanium plate, titanium and titanium alloy have weldability only under the condition of preventing violent reaction with gas.In order to obtain high quality welded joints, the following points must be noted:
(1) strictly control the harmful impurities in the base material and welding materials, especially the content of hydrogen, oxygen, nitrogen and other interstitial elements, and strictly clean the workpiece, welding materials and equipment before welding;
(2) protect welding seams and heat-affected areas with high purity inert gas, oxygen-free flux or vacuum conditions, so that they are free from gas pollution during welding and cooling;
(3) correct selection of welding wire;
(4) as far as possible, use welding specifications with low line energy to reduce the tendency of metal overheating.
One. welding process of titanium and titanium alloy plate
In titanium equipment manufacturing, the more commonly used is the melt welding, its process is generally: cutting or preparing material groove - except hydrogen - surface cleaning - workpiece clamping - welding - weld inspection.
Filler metal is welding wire, its diameter is generally 1~3mm.When the thickness of fusion welding is relatively thick (generally more than 3mm), non-melting electrode welding needs welding wire, melting electrode welding electrode itself is welding wire.The shielding gas is generally argon and pure argon (Ar>99.99%) with its dew point below -60℃.Helium gas is sometimes used only in the deep welding position.
Two. Welding method of titanium and titanium alloy plate
Titanium plate welding, titanium plate, titanium and titanium alloy welding, in addition to oxyacetylene welding, hydrogen welding, carbon dioxide gas welding and other welding should not be used, used in common metal welding methods are almost applicable to titanium.In the manufacturing process of domestic titanium equipment, almost 5% of welding work is completed by manual argon tungsten arc welding.Tungsten - general selection of cerium tungsten electrode is better.Non-melting tungsten electrode welding is often used for small, seam welding without welding wire, but also can be used for filling welding wire wide weld, its disadvantage is that in the welding I may be affected by tungsten electrode pollution weld quality.Plasma welding special welding has the advantages of concentrated energy, single-side welding and double-side forming, small arc length change to the penetration degree of multi-ti, no tungsten, less porosity and good joint performance, which is very suitable for fc and titanium alloy welding.Vacuum electron beam welding automation degree is high, but the equipment price is high, high welding cost, generally used for poor welding performance of titanium alloy, and welding quality requirements of aviation, aerospace parts.