depend e We Support Your Inspection Needs Wherever You Go! �� �� �� �� �� �� �� �� �� �� �� �� �� �� �� �� �� ! Inspection Trends / Summer 2013 25 of the parts fractured (Fig. 5), the other did not, so I did a couple more from the second process. Again, one broke and one did not though there was evidence of cracks initiating from the area of the arc strike on the one that did not fracture — Fig. 6. To my way of thinking, these ground parts were not performing very favorably. Fifty percent are not good odds, especially when human lives are in the balance. I don’t know how this would have gone, as far as percentages, if say 100 samples were tested, but even if you got it down to 10% breakage, I still don’t like the odds. It may become a question of the severity of the arc strike. Some strikes may grind down successfully while others may not. Next, I tried one more thing. I took parts with arc strikes and welded across the damaged area, then sanded them down. During these tests, I ran four coupons through the bender and not one broke, not even a visible crack or blemish — Fig. 7. One more point: when I did these tests, I did not have access to a magnetic particle yoke. Instead, I did a visual inspection using a 4× magnifying glass. Sometimes I saw some cracking, sometimes not. But my purpose was to simulate what I often see in shops, which is that if anything is done at all it gets ground down and is then let go. Conclusions The following are my conclusions: 1) When I speak with welders, the results of these tests have changed the way many of them look at arc strikes. 2) I now try to look over the whole member when doing inspections because I don’t like the odds if I miss an arc strike. 3) If the welders are working to the requirements of D1.1, I can’t insist on anything other than grinding unless the MT technician finds signs of cracking after the grinding operation. But in my own small fabrication shop, we weld them and then grind them down to a smooth contour. 4) It is not my intent to interpret or define arc strikes. Neither is it my intent to insist they be dealt with in any particular fashion. The codes and other AWS reference materials handle those responsibilities just fine. 5) It is my intent to make sure that we as inspectors understand the importance of the cautions expressed in the codes and are doing our best to handle a discontinuity that seems to be getting far less attention than it deserves. Arc strikes are going to happen. My understanding of the use of the phrase “should be avoided” is that it is impossible to eliminate arc strikes completely. But, the terminology that they “shall” be ground smooth and reinspected when found makes it clear that arc strikes must be given careful attention. 6) Finally, we as educated, trained, informed, and certified inspectors have an obligation to take every opportunity to advance the understanding of welders, managers, and in-house quality control (QC) personnel to the potential danger of letting arc strikes go by with such low levels of consideration. Arc strikes need to be searched for with at least some degree of diligence. As I walk by a member that has been completed and inspected by the inhouse QC person, I can cover a piece fairly quickly and still look at it close enough to catch most arc strikes without slowing down my process. But, beyond my time involved, if I have the understanding and cooperation of welders, management, and QC, then I should hardly ever find an arc strike that hasn’t already been dealt with. My questions to you are, do you inspect the entire member? Do you insist arc strikes be ground down per D1.1 and then reinspected? That is the least you should be doing. BRENT E. BOLING (inspector@arctechwelding.com) is president of Arc-Tech Welding, Inc., Prescott Valley, Ariz. He is also an AWS CWI with a Bolting Endorsement, an ASNT Level II in VT, and chair of the AWS Arizona Section and its Certification Committee. “We create dependability and competitiveness in services, products, businesses and people.” h r v Supervision and eeds quality control of fabrication and welding manufacturing Conventional and advanced inspection, and non-destructive testing for maintenance of industrial facilities and construction of new facilities such as: ������ Mechanical testing laboratories ����Qualification of welding processes and certification of welders ����Third-party evaluations We are experts in the following areas: �� ����Oil extraction �� �� ����Oil refining ����Petrochemistry ����Pipelines ����Energy (thermoelectric, geoelectric, hydroelectric, and aeolic). ����Aeronautics ����Industrial construction, metal buildings, concrete, iron and steel, and cellulose Headquarters: Queretaro, Mexico. www.istuc.com / istucsc@istuc.com �� �� Contact us in Mexico, Ph: (52)-442-2201486 201486 y y 2201699 For info go to www.aws.org/ad-index
Inspection Trends | Summer 2013
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