Welding coupon bend test

Welding coupon bend test

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3/8 stainless steel horiz bend test

This is about passing the AWS D1. The purpose of this web page is to help anyone out there who is about to take these tests understand the welding procedure, and help give them a visual understanding of this welding certification. As the old saying states, a picture is worth a thousand words! It also certifies you to do fillet welds on pipe with a minimum diameter of 24 inches. Plate is very easy to prepare compared to time involved in setting up pipe coupons. The 3G and 4G combo welding certification are the next best thing and are easy to pass.

These welding certifications can be used for most industries and should be the bare minimum for anyone who is going to welding school! Yeah you could get a job with just a 3G welding cert, but going back to school later is not that easy! The AWS D1. When combined with the 4G welding certification this certifies you to weld in the flat, horizontal, vertical, and overhead positions, including pipe that has a minimum diameter of 24 inches.

This welding certification comes in two thicknesses. Personally if I had a choice, I would go with the one inch thick procedure. The 1 inch thick plate is an unlimited thickness procedure, but the school I am certifying at does not offer that procedure. As with most welding certifications the AWS D1. This welding certification is valid for 6 months, or days, and if the welder does not weld with this process for six months, it expires worthless. On the back page of the welding certification there is a log table for either an employer or welding school to sign every six months.

This provides documented proof that you have been using this welding process you are certified in. The machine I used was a Miller Dialarc set at about amps. This is the amperage I was most comfortable with when I set my machine on a piece of scrap metal welding vertical up. This amperage is figured out by using the amperage range of 35 to Then taking the higher number, minus the lower number, — 35 and you get 12 amps.

The dial setting I am using has a range of 1 to 10; each number on the dial is worth 12 amps. So the starting amperage is 35 amps and then you multiple 12 by the number that the dial is set at. That equals amps. There is no right or wrong setting for this procedure, as long as you are within the procedure specifications of 90 to amps.

The procedure states in the notes how to prepare the test coupons. Here are the AWS D1. Grind off all oxidation on the bevel to bare metal. Re-check the bevel angle for the correct angle. Grind all the hot scale off the backing bar to clean metal. The inspector will check the preparation before fitting-up test pieces. After the fit-up is completed the inspector will check all the fit-up specifications. Now the test will be placed in the fixed position. The test piece will be marked in position with a marker and the inspector may see the test anytime during the testing.

The root pace shall be inspected. Required temperatures. Minimum preheat and interpass temperatures shall be as follows. When the base temperatures is below 32 degrees, the base metal shall be preheated to a minimum of 70 degrees and the minimum interpass temperature shall be maintained during welding. As the AWS D1. This is how the test coupons looked before any grinding or tacking. This is a picture of the mill scale ground back a minimum of 1" on the face of the bevel, with the oxidation on the bevel grind-ed to bare metal, and the backing bar grind-ed to bare metal.

Each right on the mark of The procedure states the total bevel angle needs to be between 45 degrees and 55 degrees. I am well within the tolerance of the procedure. They are inspected and I get to go to move on. The pictures below are of how I set-up the test plates. First I tacked one side of the bevel to the backing bar. When one side is tacked I used a vice to make sure the bevel is sitting flat on the backing bar.

Once I set the root opening and have one side tacked, I use a vice to clamp down the bevels to the backing bar and tack it into place. Finally I tacked the middle of the plate to the backing bar using the vice again. This is done to keep the backing bar flat against the bevel. The plates are put into position and inspected. The arm holding the plates is marked in many places to ensure I do not move the test coupon when welding or cleaning.

Starting the root weld did not require a preheat as the temperature was about 70 degrees outside. To start the root I got comfortable and started to weld. The technique I used was a side to side weave. I hold the sides of the bevel where the bevels edge feathers into the backing bar until I could see the arc of the electrode start to roll to that side. Once the arc is rolled and the flux is burned off on that side of the electrode, I weave onto the other side, and keep repeating that process.

By allowing the arc to roll on the electrode it penetrates the bevel and gives the electrode a chance to ride up on the bevel for a moment. This helps to avoid slag inclusions. I used three welding electrodes and had two restarts. The root weld was cleaned with a wire wheel and as the procedure states it was inspected. This is done because it is in the welding procedure and in the words of the American Welding Society:. A concave root surface is permitted within the limits shown below, providing the total weld thickness is equal to or greater than that of the base metal.

Before moving onto the hot pass or filler pass, I let the plate cool till I could almost touch it with my hand. Second I did take a grinder and lightly ground the root pass. I did not need to do this, but why take a chance! Here is the root weld ground down. For the hot pass or fill pass I used the same technique as the root weld. That is holding the sides and rolling the arc until the weld rides up onto the side of the bevel. I used four electrodes and had three restarts.

Again I waited for the plate to cool and lightly grinded it down. I did not have to grind it, but why risk getting a slag inclusion. As you can see the first restart was a little rough. The cap was done using a weave technique holding the corner of the bevel until it was filled and the moving onto the other side. If you do not wash weld properly into the corner of the bevel you run the chance of not penetrating the test coupon properly.

On the cap of the weld I used four electrodes. Here are the picture of the cap weld. Here is where I held the electrodes when weaving the cap of the weld. As you can see the center of the electrode needs to be directly on the corner of the bevel. This gives the cap good penetration into the test coupon and keeps the risk of a face bend break to a minimum. This is the finished weld and cleaned with a wire wheel.

It is well within the acceptance criteria. In the words of the American Welding Society:. Preparing test coupons for a bend test is not difficult but it does require taking your time and doing it right. There are a few steps that need to be followed otherwise you may fail this test based on preparation! It is now the next day since taking the test and the plate has had more than enough time to cool.

The first thing is to put a mark in the center of the plate with soap stone. Then you need to put a mark one inch above it and one inch below it. The two outside marks are the bend specimens. Using a square I marked lines across the test plate as to where they will be cut. In the case of coupon failure the middle of the plate can be used as a backup coupon, as long as the failure of the bend falls within the AWS acceptance criteria for a bend test.

Next my initials are inscribed, and the bend test specimens are marked, one for a root bend, the second for a face bend, and the third for an alternate. The test coupons are cut on a band saw. Now it is time to remove the backing bar off the test specimens. I did this by grinding the area where the root penetrates the backing bar. I grind just close enough to where I could lock on to the split backing bar with a vice.

Then I put the backing bar into the vice with one side of the backing bar locked and pushed down with my hand on the coupon like a lever. The backing bar came off very easily.

Weld Test Coupon

Powered by mwForum 2. Not logged in American Welding Society Forum. By goldybowen21 Date I ve been asked to find the sizes and materials list for the test coupons going to be used for testing from 1" to 6" A where would I find the test coupon sizes I need to find them today also so any advice or direction would be helpful.

Guided bend tests provide a quality control check that helps determine the ductility of weld metal at the face and root of a welded joint. A guided bend test sample containing the weld is located at its center point while being supported by lower anvils.

This is about passing the AWS D1. The purpose of this web page is to help anyone out there who is about to take these tests understand the welding procedure, and help give them a visual understanding of this welding certification. As the old saying states, a picture is worth a thousand words! It also certifies you to do fillet welds on pipe with a minimum diameter of 24 inches. Plate is very easy to prepare compared to time involved in setting up pipe coupons. The 3G and 4G combo welding certification are the next best thing and are easy to pass.

Guided Bend Test of Metal Welds

The above pictures are a structural welding certification given by the American Welding Society. The very basics of a welding welding certification are:. Welding certifications are also documented to prove that the welder is qualified under that code. Welding codes vary a lot depending on the type of work being done. There are many organizations that have different procedures depending on the type of work they oversee. In the United States there are quite a few organizations that have certified welding procedures.

WATCH THE VIDEO ON THEME: Bending Test (Welding Inspector)

Weld inspection before you weld

Remember Me? Page 1 of 2 1 2 Last Jump to page: Results 1 to 25 of Welding "coupons" question. Thread Tools Show Printable Version. Welding "coupons" question Ive seen so many videos of folks welding the coupons and then bend testing. Well I wanted to try it just for my own amusement! Am I doing it "right? Then it occurred to me that perhaps people who are actually taking the test can t weld both sides?

Everyday our testing and inspection labs process welding coupons, in the form of pipes and plates for companies who are getting their weld procedures qualified and welders certified. Many companies and industries including contractors, manufacturers, educational institutions, utilities, oil and gas suppliers use our testing facility. ATS has several options for testing and qualifying coupon specimens. The first option is to ship or drop off your welding coupon. Then, we will perform the requested tests on the specimen per the applicable codes.

Welder Qualification Testing

While patrolling a shop floor playing "parameter police," a welding inspector may commonly hear questions like "Why can t I run my machine above XXX wire feed speed? Welding parameters aren t guidelines merely plucked out of thin air; they are developed and determined after much trial and error. By standardizing the welding procedures you use to manufacture your products, you ll have a model that everyone can turn to for quality assurance. In procedure qualification testing, you may find it helpful to try to complete all testing using readily available resources. Completing testing on one groove weld typically qualifies all groove types and fillets. Changes in essential variables, however, often require additional testing. For example, in the off-road, agriculture, and construction equipment manufacturing industry, customers often require fillet welds to obtain penetration beyond the root, typically 1. Many codes and standards require penetration to the root, "

What are Weld Test Coupons?

Powered by mwForum 2. Not logged in American Welding Society Forum. By Tate48 Date Hello all, I have posted once before and found this is the place for great help. I teach at two schools and found that people have two ways of doing things. I was taught that when prepearing side bend coupons to be bent to D 1. While observing at the other site I notice they cut the coupons and remove the backing then bend them as as. We looked in the code book D1.

Basic test.

Bend testing

For the weld procedure that those coupons were used for, there was a series of inspection criteria that must be met before the welder becomes qualified on that procedure. First, the welder completes the root pass and it must be visually inspected VT and approved by the welding inspector before being allowed to proceed. When the coupon is welded out, and a final visual acceptance of the weld is done, the weld is ready for either non-destructive testing NDT or destructive testing DT depending on the type of weld. After passing the RT criteria, the coupon moved on to destructive testing. For DT on these coupons, there was a total of 12 straps cut out and prepped for testing. Eight straps were used for nick break tests, two straps for root bend tests, and two straps for face bend tests. The nick tests are performed to expose internal imperfections such as slag inclusions, lack of fusion, incomplete penetration, porosity, etc. To do this, a notch or nick is intentionally made by a cutting the strap on the weld face to help it fracture in the center line of the weld. The strap is then mechanically bent to fracture it and the cross section is visually examined for any imperfections. The root and face bends are done in a similar fashion, but used to test the ductility of the weld with the base material. One set of straps is bent with the face of the weld to the outside, and the other set is bent with the root of the weld to the outside. The idea here is that the weld metal and base material should plastically deform together, and not fracture or fail.

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The above pictures are a structural welding certification given by the American Welding Society. The very basics of a welding welding certification are:. Welding certifications are also documented to prove that the welder is qualified under that code. Welding codes vary a lot depending on the type of work being done. There are many organizations that have different procedures depending on the type of work they oversee. In the United States there are quite a few organizations that have certified welding procedures. The three largest organizations are:. The largest organization in America that certifies welders is the American Welding Society. The welding certification procedures they have approved have been tested many time to ensure that if followed the welder taking the welding certification follows the rules and has the skills will pass the test.

49 CFR Appendix C_to_part_ - Qualification of Welders for Low Stress Level Pipe

The bend test is a simple and inexpensive qualitative test that can be used to evaluate both the ductility and soundness of a material. It is often used as a quality control test for butt-welded joints, having the advantage of simplicity of both test piece and equipment. No expensive test equipment is needed, test specimens are easily prepared and the test can, if required, be carried out on the shop floor as a quality control test to ensure consistency in production. The outside of the bend is extensively plastically deformed so that any defects in, or embrittlement of, the material will be revealed by the premature failure of the coupon. The guided bend test is where the coupon is wrapped around a former of a specified diameter and is the type of test specified in the welding procedure and welder qualification specifications. As the guided bend test is the only form of bend test specified in welding qualification specifications it is the only one that will be dealt with in this article. The strain applied to the specimen depends on the diameter of the former around which the coupon is bent and this is related to the thickness of the coupon t , normally expressed as a multiple of t eg 3t, 4t etc. The former diameter is specified in the test standard and varies with the strength and ductility of the material - the bend former diameter for a low ductility material such as a fully hard aluminium alloy may be as large as 8t. An annealed low carbon steel on the other hand may require a former diameter of only 3t. On completion of the test the coupon is examined for defects that may have opened up on the tension face. Most specifications regard a defect over 3mm in length as being cause for rejection. For butt weld procedure and welder qualification testing the bend coupons may be oriented transverse or parallel to the welding direction. Below approximately 12mm material thickness transverse specimens are usually tested with the root or face of the weld in tension.

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Comments: 2
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