NDT Testing of Arc Welding

Welding is a fabrication process used to join materials, usually metals or thermoplastics, together. During welding, the pieces to be joined (the work pieces) are melted at the joining interface and usually a filler material is added to form a pool of molten material (the weld pool) that solidifies to become a strong joint. A welded structure must be safe and reliable. It is often said that the integrity of a weldment can be achieved only when welding design, welding fabrication, material, and welding skill are all appropriate. In testing, a weldment is examined according to a specific procedure, and the test results are presented in a certain written format. In inspection, the results are checked whether they satisfy the criteria of the specification and they have to be judged by an inspector. Various NDT test and inspection method are carried out according to the specification required, considering the type of structure and the environmental factors such as operational temperature, corrosion and mechanical wear involved in the operation. To guaranty the quality of welded structure Inspection should be conducted throughout the period during the welding fabrication.