What is backing strip used for?
The use of ceramic backing strips enables welding to be carried out from a single side, with full penetration and reduces (and often removes) the need to grind out and re-weld a root from the reverse side. The strips are available in a range of configurations for differing applications and resulting weld bead shapes.
What is the backing in welding?
Backing is defined as material placed at the root of a weld joint for the purpose of supporting molten weld metal. Its function is to facilitate complete joint penetration.
What is retainer in welding?
2) Retainer: US terminology for a non-consumable material, either metallic or non-metallic, that is used to contain or shape the molten root run is a ‘retainer’.
What is difference between back and backing welds?
A back weld is when a weld is created on the back side of the joint after the groove weld is performed. A backing weld is applied to the root of a groove before welding the groove. Therefore, a note in the tail of the welding symbol may specify which type of weld is required or it may be specified in the legend.
What is ceramic backing in welding?
Ceramic backings are made of sealed, high temperature resistant ceramic, from different mineral mixes (e.g. Al2O3, SiO2, Fe2O3, TiO2). When they melt, they produce a glassy slag that forms the underside of the weld seam and seals it against air entering. They are chemically neutral in the weld pool.
What is low hydrogen welding electrodes?
Low-hydrogen electrodes, most simply defined, are SMAW consumables that contain less than 0.6\% coating moisture — compared to 4 to 6\% moisture in traditional cellulosic electrode coatings. The lower moisture levels correspond to relatively lower diffusible hydrogen levels in the deposited weld metal.
What are the 5 basic types of welding joints?
There are five basic welding joint types commonly used in the industry, according to the AWS:
- Butt joint.
- Tee joint.
- Corner joint.
- Lap joint.
- Edge joint.
What is puddle weld?
An arc spot weld also referred to as a puddle weld, or a plug weld, is the method used for welding steel decking to the supporting steel framing below. It penetrates into the steel beams, steel trusses, or open web joists beneath it and attaches the the metal deck.
What is Corner joint?
4 The corner joint. The corner joint may be regarded as a butt joint and is used to join two plates at right angles to each other (Fig. 5.4f). It can be difficult to assemble and maintain correct alignment, particularly in thin flexible sheet.
What are the 5 welding joints?