SMAW for 304 stainless 3

[kellnerp]

We had a bit of discussion regarding stick welding 304 stainless in the vertical position. 308L-15 is the rod that is recommended for vertical welds in this material. However, 308L-16 seems to be what is commonly available. What are the pros and cons to using -16 over -15 in this application? We want to make a vertical but weld in 1/4" material.

TIA

 

[metengr]

Here is an excerpt out of the Welding Handbook of Stainless Steel products from esab.

"Lime...coatings, also known as lime fluorspar or basic, are generally associated with the suffix -15 designation. They give the cleanest weld metal, which is usually the lowest oxygen and inclusions and are more resistant to moisture and porosity. The weld metal tends to be tougher, more ductile, more crack resistant and have higher corrosion resistance. They also have good all-position characteristics and are often chosen for site work. They are normally usable only with direct current and should be the choice of the most demanding applications.

AC-DC...coatings can be used with alternating or direct current and have the suffix -16. The major component is rutile, also known an titania, with some limestone which is why the coating type is sometimes referred to as basic-rutile. These AC-DC electrodes are the most popular type, and have the following characteristics: excellent starting properties are obtained with all types of AC welding equipment. The arc is stable, smooth, with fine spray weld metal transfer and the bead is uniform, flat or slightly concave with straight-line feathered edges. Penetration is complete and the weld metal is free from porosity. Slag is easily and completely removed without secondary film which means less cleaning, grinding and polishing time. Arcaloy AC-DC electrodes give good out-of-position characteristics. The mechanical properties of AC-DC weld metals are similar to weld metal from lime coated electrodes except it can be stronger with good ductility."

I have seen both E308L-15 and 16 produce similar results.

 

[stanweld]

Our standard practice to weld vertical up uses -16 electrodes due to ease of welding and bead appearance; -15 electrodes are specified for welding materials used in cryogenic applications.

 

[kellnerp]

This will be a corrosive environment. Why spec -15 for cryogenic?

 

[nycpipewelder]

The 15 in my opinion is alot easier to run in any position Metengr is right about the flux. The problem I found was that alot of suppliers won't stock all the different rods that are made I was looking for 309-15 and told the 309-16 is industry standerd but when I worked on a Chicago Bridge & Iron work job 309-15 was there industry standard

 

[stanweld]

kellnerp
As metengr stated, the -15 produces a "cleaner" weld and as a result is more likely to meet impact toughness requirements of various design Codes at cryogenic temperatures of -320 F. Impact toughness at -320 F is sometimes unobtainable with the -16 electrode, primarily due to increased oxygen content in the deposited weld metal.