308 L16 vs. 308 L17 stainless steel rod

Date 10-25-2011 02:39 Edited 10-25-2011 02:44

Arcaloy 308L-17 Plus electrodes have a heavy coating, produce a concave bead with minimum ripple and the slag is virtually self-cleaning. These electrodes are designed to weld Types 304, 304L, 321 and 347 for corrosion service at temperature up to about 600ºF(315ºC).
The excellent wetting action and very fine ripple minimize crevice corrosion and grinding time. This is particularly useful in the food and drink industry where a smooth polished surface is required.

Arcaloy 308L-16 electrodes were developed for the welding of Type 304L stainless steels but can be used for many other stainless steels including Types 301, 302 & 304. They are used extensively for the welding of chemical plant equipment and may be used successfully for the welding of Types 321 and 347 stainless steels provided the service temperature is less than about 700ºF(375ºC). The basic-rutile thin coating of Arcaloy 308L-16 gives an excellent combination of welding performance in all positions and a high resistance to cracking.

To determine the best usage we need to now more about the job. Is there a code involved?

By 803056

Date 10-25-2011 21:36 Edited 10-25-2011 21:53

The "L" following the alloy type indicates "low carbon", a consideration when sensitization is a concern. EXXXL-15, EXXXL-16, and EXXXL-17 are all low carbon versions of EXXX-15, 16, and -17 covered electrodes. The low carbon reduces the tendency to produce M23C6 (chrome carbides)along the grain boundaries which are subject to accelerated corrosion along said grain boundaries especially in the presence of halides such as chlorides in the "water". Stress corrosion cracking can also be a concern.

The separation between the XXX-16 and XXX-17 suffixes is relatively new. The XXX-17 was originally included in the XXX-16, but was assigned a separate classification due to the increased silicon which produces a more fluid weld pool. The fluidity of the weld pool makes it difficult to control the weld pool when welding grooves in any position other than flat. Likewise when welding fillets in the vertical and overhead positions.

The XXX-16 contains less silicon, the weld pool isn't as fluid as that produced by the XXX-17, but out of position welding can be a challenge.

The XXX-15 classification utilizes a limestone flux covering and is better suited for welding out of position and for depositing fillet welds in any position. It provides better penetration than the XXX-16 or XXX-17 electrodes. As a matter of fact, I have yet to have a contractor pass a simple fillet break test in the horizontal position. Several people here in the forum have said they have had success, but I've worked with many contractors that have not experienced good results with anything other than XXX-15 covered electrodes. The XXX-15 electrodes use a Limestone based flux covering which requires a heated electrode oven per D1.6. Actually, if I recollect, D1.6 requires all XXX-15, -16, and -17 covered electrodes to be stored in heated ovens. I'm not sure why, but check D1.6 for yourself.

Since ASME piping codes are sparse on information regarding matching electrodes for various base metals, you might want to consider reviewing AWS D1.6 and AWS D10.X for some direction. (I would give you the correct AWS D10.X, but I can't find mine on my desk top.)

Best regards - Al