I am not sure of what the code is trying to say so I am posting this question. I hope someone can clarify. The paragraph relates to acceptance criteria for bend tests. It says the convex surface (of the bend test) shall be acceptable if it contains no conditions exceeding the following :
1) I understand this condition, no discontinuities over 1/8" size
2) I understand this condition, no discontinuities that are between 1/32" to 1/8" and, when summed, are over 3/8"
3) 1/4" - maximum corner crack, except when crack is result of slag inclusion or other fusion problem, then 1/8" rule applies. OK I get this. But then it states that corner cracks exceeding 1/4" with no evidence of inclusions or fusion problems shall be disregarded and another specimen should be tested. Isn't that contradicting the first part of (3)? Are corner cracks made as a result of slag inclusions or fusion problems and are bigger that 1/8" then the only condition to reject ? Or are corner cracks that are 1/4" max and not a result of inclusion or fusion problems reject too, but if similar corner crack is over 1/4" then retest another specimen ? Seems if a 1/4" corner crack is reject, one over 1/4" should be too. Please help - thanks in advance. JAL
Jim,
1/4 inch is the max allowable corner crack when not resulting from inclusions or other discontinuities, IE porosity. When the corner crack is a result of inclusions or other discontinuities, IE porosity, 1/8 inch is max. Over 1/4 inch corner crack is rejectable regaurdless of cause. I am not by any means trying to sound condescending, but read it again a little slower as it is really pretty well explained in D1.1.
By bmaas1 
Date 04-01-2008 17:13
Edited 04-01-2008 17:15
Specimens with corner cracks exceeding 1/4" with no evidence of slag inclusions or other fusion type discontinuities shall be disregarded, and a replacement test specimen from the original weldment shall be tested. This can happen if you do not knock the edges off your specimens properly leaving a sharp corner.
Brian
bmaas1/Brian has a very good point. I have seen many a failed weld test specimen resulting from not grinding a slight radius on the edges. Look at figures 4.12 and 4.13 and both face and root specimens as well as side specimens can have 1/8" maximum radius. I have found that approximatly 1/16" works better, as 1/8" is listed as a maximum.
So over 1/4" corner crack is reject unless it is caused by fusion problem or inclusion, then over 1/8" corner crack is reject. Got it. But if a corner crack is caused by sharp corners and bending forces during bending, then disregard it and test a new specimen from original weld. Good enough, thanks. JAL
Almost... 1/4" and under is not rejectable unless it is caused by fusion problem or inclusion. Over 1/4" is rejectable reguardless, disregard it and test a new specimen from original weld.
Right. Disregard (ie ignore) a reject corner crack over 1/4" when that corner crack isn't caused by an inclusion or other fusion problems, and cut a new specimen and test it, making sure the sharp corners and all are rounded off on the new specimen. I just did't understand why the need to retest when a reject condition exists, but like you say, that's what the code says to do. I suppose the retest is to support (or not) the conclusions reached from the first specimen. Anyway, thanks for your help. JAL
Anytime, glad to help. jrw
