I have a question on AWS D17.1 code with the macro examination. When you are doing an autogenous weld (with no filler wire) how are you suppose to pass a macro examination? The code states that the weld needs to be 1.5T. Since you don’t add filler material, its tough to make the weld bigger than what it is stating. This is for material Inconel 625, 22g, Lap Joint.
Just to add in this thread... If there's anyone that knows more about D17.1 here well, I haven't seen that person post yet and Lawrence is the resident expert on that specific code/standard... So you're very fortunate to have him answer your query and if I were you, I would make note of any advice he gives you for free because I know that his consultation fees are not cheap! Lawrence is well known in his expertise regarding welding matters related to AWS D17.1... Answer his questions and you should get the best advice for your query! Oh and I almost forgot to: "WELDCOME TO THE WORLD'S GREATEST WELDING FORUM!!!"
Yes, I am refering to leg length and the welds will be a concave profile. Its per AWS D17.1:2010, A4.1 states that the fillet weld needs to be 1.5T ...i believe its page 45.
Thank you very much for helping me with this question. I very much appreciate your time and thank for welcoming me to the forum!! I plan on using these forums since I am a new weld engineer here. I figured this would be a good knowledge base to grow from. THANKS AGAIN!!
Is there anything I am missing to contribute to this question?
Your quote is from the Annex, which presents a teachable moment for others in that; *UNLIKE* other AWS DXXX codes, the annex contains *mandatory* information.
A4.1 says "...The suggested minimum weld size for a single fillet weld is 1.5 times the thickness of the thinner member..."
Not that I would hang my hat on doing less than the code call out because it's a suggestion... Not at all.
So you need to ask yourself; "Are the weld profiles concave for engineering/airflow/fitup reasons? Or are they concave because the welding operator on the floor is handing you plates with a concave profile?
Secondly... It is perfectly reasonable for you to expect your manual welding operators to make a lap weld on 0.031 (22ga) inconel 625 that has a convex or flat face contour that meets the code "suggestion" you cited in your OP.
There are some subtle technique variations that operators use to achieve this.... I say this with confidence because I have personally welded miles of this profile with this exact alloy and thickness and trained dozens of others as well. :)
An 0.040 tungsten electrode with a very long pointed tip is a good place to start... The extra slim tip preparation will make for easy arc starts and allow the operator to get VERY close to the work. The electrode is held perpendicular to the joint (meaning no push no drag angle) and is positioned slightly (about .020) over the top plate rather than pointed into the root of the joint. The slim taper actually blurs the arc plasma cone and makes it less conical... Which in this case is what you want.
The arc is struck and the current is increased slightly as the electrode is brought ever closer to the work until the edge of the top plate breaks down and fuses to the bottom plate... The operator at that point moves forward with the tungsten electrode actually *BELOW* the level of the top plate as the metal breaks down before it and flows into the new *Convex* profile weld.
Edit: Last technique tip... Inco 625 even fresh from the mill or covered with a plastic coating will have an oxide layer that can make these tight little welds more difficult.. Stainless wire toothbrush or scotch brite to remove the oxide from the weld area just prior to work is another key to quality..... Acetone wipe never hurts either.
justing86 you know I think you have answered your on question.When you are doing an autogenous weld (with no filler wire) how are you suppose to pass a macro examination? The 1.5T size is talking about a fillet weld. Maybe you need to pass a fillet weld to do a autogenous weld.
I also have come across a different question here for D17.1.
I am also working a Alloy 188, 16ga, groove weld (butt joint) with filler material. My question is on the max root opening and the max reinforcement. Table 7.1 on page 34 is telling me I can have a reifnorcement up to 1T so in my case....my max reinforcment can be up to .048". Now for my max root opening,I go to figure a.1 on page 46. Its telling me I can have a root opening on 1/2T...so in my case again I can have up to .024"
I'm basicly just doing a double check here. When i first started with this code....I thought I remeber reading somewhere that my max weld reinforcement was .010" and my gap was no more than .030". I'm probably yjust being paranoid.
"Weldcome" Justing86!
