Metallurgical Principles and Practice of Engineering (PE) Study Guide: Question #51

It Is the Policy of The Minerals, Metals & Materials Society (TMS) to Encourage the Professional Registration of Metallurgical Engineers.
Carbon steel piping was welded using Gas Tungsten Arc Welding (GTAW). The piping was installed and hydrostatically tested. During the hydrostatic test, one of the weld joints started to leak. Visual examination of the weld cap revealed what appeared to be a leak originating along the area of the fusion line between the base metal and the weld metal. An exposure using radiography, taken parallel to the location of the suspected leak, failed to reveal evidence of a crack. However, several white or bright spherical indications were observed on the radiography film. Cross-sections taken through the weld, confirmed lack of fusion between the weld metal and the base metal. Considering the information presented, which of the following statements is most accurate?

(A)	Lack of fusion can be caused by inadequate welding speed and excessive welding current. The spherical indications on the radiography film were porosity.
(B)	Lack of fusion can be caused by inadequate welding current and improper fit up. The spherical indications on the radiography film were porosity.
(C)	Lack of fusion can be caused by excessive welding speed and inadequate welding current. The spherical indications on the radiography film were tungsten inclusions.
(D)	Lack of fusion can be caused by postweld heat treatment and inadequate welding current. The spherical indications on the radiography film were tungsten inclusions.

The information on this page is maintained by the Nellie Luther (natale@tms.org).

Search PE Study Guide TMS Education Page About TMS TMS OnLine