A-36 to 17-4PH stainless MACRO ETCH TEST

Date 05-20-2013 21:49 Edited 05-20-2013 21:52

I hate to throw stones, but one of the objectives is to deposit a weld with equal legs.

Next, the final polish needs to be done with finer grit. I use a granite surface plate with 1200 grit for the final polish. It is a pain in the ass, but the surfaces have to be perfectly flat when the sample is ready for the etch. Start with something like a 400 grit, progress to 600, then 800 and 1000 grit. Each polishing operation should be oriented 90 degrees to the previous operation. Like I said, the final operation should be with the 1200 grit. Cut away the excess material (butting and nonbutting) before starting the preparation will make the job easier. That way you are only polishing the cross section of the weld and a little base metal.

If you look at the third photo, there appears to be incomplete fusion in the root extending up on both the butting member and the nonbutting members.

A better polish and close scrutiny will most likely show a similar problem with the other samples.

It is interesting to note the void in the root. It shouldn't be there.

Best regards - Al

By MRWeldSoCal (***)

Date 05-20-2013 22:26

throw all the stones you want, i can take it. good idea to cut down the plates to get just the important part and sand that. ill be sure to do that next time. going to order some -15 tomorrow

thanks again

Jordan

By cddolan74 (**)

Date 05-21-2013 12:27

Jordan,
you will find the -15 coating a less stable arc than the -16. you should not be getting incomplete fusion at the root. always hard to make suggestions when not being able to see the task performed. could only think that the welder is not holding tight enough arc to ensure penetration.

By MRWeldSoCal (***)

Date 05-21-2013 14:23

When I went to the 3/32 the roots came out a lot better. I was told maybe a little more rod angle to help blow slag a bit furthur back and use the arc blow to my benifit.

By cddolan74 (**)

Date 05-21-2013 18:52

that's true. I did see your repost on the 3/32 and saw possibly a little incomplete penetration at the root. I have not seen the problem with slag inclusions from the -16, -17 coatings that someone else posted. Curios to who makes the covered electrode your using. I have bench marked a lot of different manufacturers to compare arc stability, slag formation and detachment.

By 803056

Date 05-21-2013 22:23

I have clients that have used Lincoln Blue Max and ESAB. In both cases (using both Lincoln and ESAB electrode) only the E309-15 could produce fillets with fusion to the root. Both the -16 and -17 covered electrodes had a nice line of slag and incomplete fusion in the root.

We had similar problems with E308 and E316 SMAW electrodes as well. Only the EXXX-15 produced acceptable results in the horizontal positions when depositing fillet welds.

We tried low current, high current, changing the lead angle, I even pushed the electrode into the root with enough force that the rod bent slightly as I progressed along the joint. All to no avail until we switched to the -15 covered electrodes. We tried 3/32, 1/8, and 5/32 inch diameter electrodes.

We had good results with the -15 covered electrodes. The jobs entailed a substantial amount of welding; all of it subject to visual inspection.

The Engineer wanted to MT all the welds, but I vetoed that pretty quickly and put the matter to rest with a demonstration.

Best regards - Al

By cddolan74 (**)

Date 05-22-2013 12:09

Al, thanks for that info that's something I would like to look into. to be clear I do work for Arcos a solid and covered electrode manufacturer. when bench marking I was looking at welding characteristics and not at this time the weld cross section. I have not had the feed back on the -16, -17 coatings producing lack of penetrations welds. My understating was the -15 coating produced better cryogenic mechanicals.

By 803056

Date 05-22-2013 14:32

Don't be bashful, send me some samples and I will be happy to run some tests.

Client's are often looking for suggestions as to which electrodes work best. I try to steer them to the classifications and brands I have experience good results with.

As you have no doubt discovered, welders don't hesitate to share their experiences with each other, both good and bad.

I this case I have not discovered the test results to be dependent on the brand, but the results differed primarily by the flux covering, i.e., -15 versus the -16 and -17.

Have you worked with the -25 and -26 coverings? I have not tried either yet, but would like to run some tests with them. It would be interesting to try an electrode that contains the alloy additions Cr and Ni in the flux covering rather than in the core wire.

Best regards - Al