single bevel groove minimum sidewall penetration

Date 02-26-2020 13:01

No mention of a welding standard or code, so I will reference AWS D1.1:2015.

4.11.3 Verification of CJP Groove WPS by Macroetch.
When a WPS has been qualified for a CJP groove weld and is applied to the welding conditions of a PJP groove weld, three macroetch cross section tests specimens shall be required to demonstrate that the specified weld size shall be equaled or exceeded.

4.9.4.1 Acceptance Criteria for Macroetch Test.
For acceptable qualification, the test specimen, when inspected visually, shall conform to the following requirements:
(1) PJP groove welds; the actual size shall be greater than the specified weld size, (E).
(2) Fillet welds shall have fusion to the root but not necessarily beyond.
(3) Minimum leg size shall meet the fillet weld size.
(4) the PJP groove welds and fillet welds shall have the following:
(a) no cracks
(b) thorough fusion between adjacent layers of weld metal and base metal
(c) weld profiles conforming to the specified detail, but with none of the variations prohibited in 5.23.(too long to type out)
(d) no undercut exceeding 1/32" in.

By cbutts

Date 02-26-2020 13:08

thanks, i guess what im trying to ask is in the groove other than the root is there a minimum depth for sidewall fusion?

By jwright650 (*****)

Date 02-26-2020 13:20

I take it as it just needs to be completely fused.....no areas of non-fusion
If the nugget has melted into the groove face, I would say that you have met the criteria.
If there is a straight edge at the groove face(bevel face) that is still recognizable, then no.

By cbutts

Date 02-26-2020 13:49

awesome thanks for your response it helped me immensly

By welderbrent (*****)

Date 02-26-2020 15:12 Edited 02-26-2020 15:14

I would agree with John,

there is no 'measurement' for how 'deep' fusion/penetration must be. Just no evidence of incomplete fusion, slag pockets, etc.

Now, depending upon code, which test, and so on, you may also be able to cut and bend some bend coupons. Sure, some will have you do RT before any other test, but doing a bend test will for sure tell you if that fusion/penetration is adequate. I can pass an RT that will not pass a bend.

Some of your tests will include tensiles, yields, and such which is also proof of the strength of the joint at your fusion points. But a good old bend test is fast and cheap to prove acceptable procedures if just trying to document a welders ability.

Depending upon code, process, and final application of the product, a bend test is often well worth the time and effort.

And, yes, the root is the only place where you need to document, in most cases anyway, that the weld goes "to the root but not necessarily beyond". (I put that in quotes even though it may not be word perfect.) I don't recall anywhere that makes any statement similar to that for the groove face(s).

Have a Great Day, Brent

By jwright650 (*****)

Date 02-26-2020 16:44

I agree with adding a side bend or two to your testing, it will show any areas where there is no fusion.

By 803056

Date 02-29-2020 16:02 Edited 02-29-2020 16:19

The do's and don'ts of performing a macroetch is not something covered by the AWS CWI Seminar.

For the most part, you will be working with acids of various types that are diluted with water or alcohol. Any acid can be dangerous if not handled properly.
Number 1 - wear proper goggles to protect your eyes, better yet, a full face shield is better.
Number 2 - wear nital gloves to protect your hands from acid burns.
Number 3 - wear acid resistant lab jacket
Number 4 - be sure there is good ventilation. The fumes can damage the lining of the throat and lungs
Number 5 - make sure there is plenty of water at hand to flush any acid that comes in contact with your skin.

Procedure - grind and polish the specimen. I use a granite surface plate with plenty of emory paper of various grits. Start with course grit. Proceed to finer grit paper, but rotate the specimen 90 degrees each time you go to a finer grit. Remove all the scratches from the previous grit before moving on to the next finer grit.

The sample should be mirror smooth when you apply the acid. AWS B2.1 has some recommendations as to which etchant to use of different base metals.

Incomplete fusion, slag inclusions, etc. will be apparent by visual differences in the appearance of the discontinuity and surrounding base metal or weld metal. Typically, a crack, incomplete fusion, etc. will be darker than the surrounding metal. As mentioned, incomplete fusion on fusion face (fillet or groove weld) will appear as a dark straight line. Depth of fusion simply means the weld is fused to the fusion face. There is no requirement that it "measure" some minimal dimension. In some cases there is a need to minimize the depth of fusion to reduce the amount of dilution, but yet there must be evidence of fusion.

Etching samples is simply a matter of controlled corrosion. Certain metals or microstructures corrode or don't corrode as fast when exposed to various acids. The process should be performed only after receiving proper instruction form someone with experience handling acids and other hazardous liquids and gases.

ASM offers a class in the proper preparation and interpretation of macroetch samples.

I went to YouTube to see what was available on the subject. There were several videos avaialble. Like many videos, there are some that are by folks that are professionals, but there is still some useful information. One video demonstrated how oven cleaner can be used to etch aluminum, Naval Jelly can be used to etch carbon steels, etc. Here's a link to a video that illustrates some common weld defects.

https://www.youtube.com/watch?v=j7O7ysXpYTI

Good luck.

Al

By jwright650 (*****)

Date 03-02-2020 12:18

Good stuff Al.....can't be to cautious with acids.
plus the better you can polish, the better the resolution,.... is a good thing for people to know as well.