03:11 Apr-22-2004 Ed Ginzel R & D, - Materials Research Institute, Canada, Joined Nov 1998 1208
Re: Can you detect Copper Inclusion with TOFD Michael: Detection of copper is difficult if just a small disolved quantity in a random location within the body of the pipe metal. Generally one looks for evidence of copper by its effect on the structure. This would generally be a dendritic cracking as copper tends to reduce toughness. To simply detect copper by diffraction or reflection off a presumed "molecular interface" is difficult if no cracking exists, this because the acoustic impedences are close enough that not much "reflection" occurs (e.g. 46MRayls for steel versus 42MRayls for copper).
If you have to look at the entire volume of a pipe for this type of subtle reflection using TOFD the probability is low that you can actually detect and correctly identify it as such with confidence that it is not some other "inclusion".
If instead of the pipe you are actually concerned for copper in the welds you may be able to improve your probable chances and confidence levels by looking for the cracking effects.
Lewis Morgan in the Nov 2003 Insight describes that the detection of copper was often misclassified but it CAN be detected.
----------- Start Original Message ----------- : I am interested in any information about detecting copper inclusion in X70 pipe using TOFD. Any help in this matter would be appreciated. ------------ End Original Message ------------