Stainless Steel Pipe Welding Procedures

Stainless steel base metals are grouped primarily into three classes depending on their crystal structure.

Stainless steel pipe welding procedures.

Tig welding stainless steel is performed by using a non disposable tungsten electrode with a tig welder for striking up the arc. Even though most of the welding machine manufacturers have included a table of materials and voltage settings in the machine it is highly important for you to pick the right kind of gas and electrode wire to be used for mig welding stainless steel. Backgroundthe new ncpwb welding procedure specification numbering system clearly defines the type of metals to be welded the welding process used and allows for identification of variations in a process. This is basically a common and unique process for joining stainless steel.

The preferred method for high purity food grade stainless steel is an autogenous tig square butt weld. The pipe welding techniques used and the procedure is also identical to the asme section ix pipe welding certification. This numbering system will be used on all welding procedure specifications revised or developed in the future. How to tig weld stainless steel.

When higher preheat is required by the applicable construction code i e. Mode of metal transfer. Welding on metal that is wet is strictly prohibited. Since welding pipe in the 6g position covers all of the pipe welding positions the information on this page can be applied to welding.

Below is a basic step by step guide to follow when welding stainless steel. Stainless steel alloys usually have a chromium content of a least 10. Austenitic such as 302 304 308 316 etc martensitic such as 410 and 416 and ferritic such as 409 and 430. This is the intro page about welding pipe and how to pass the aws b2 1 6g e6010 open root and e7018 fill and cap pipe welding certification.

In the welding procedure specification. In resistance welding lower current can be used because resistivity is higher. Stainless steels which require special welding procedures are discussed in later sections. B31 1 b31 9 etc that preheat shall be used for production welding.

The new d1 1 spells out the requirements for design procedures qualifications fabrication inspection and repair of steel structures made of tubes plate and structural shapes that are subject to either static or cyclic loading. Less welding heat is required to make a weld because the heat is not conducted away from a joint as rapidly as in carbon steel. 4 stainless steel welding characteristics by definition stainless steels are iron base alloys containing 10 or more chromium which imparts to the metal the. Tig welding is traditionally used for welding stainless steel tube and pipe and remains the optimal solution for extremely high purity applications on tube or pipe at or below 6 inch diameter and schedule 10 wall thickness.

The following describes the new numbering system welding procedure. Alternative gases that you can use are 98 argon and 2 co2 or 98 argon and 2 oxygen mix. Wet metal shall be heated until it is at least warm to the touch to assure removal of moisture.