EDDY CURRENT DEFECTOSCOPES (TOKOVIKHREVYE DEFECTOSCOPES),
Abstract
Several new eddy-current flaw detectors were developed recently at an unidentified plant. The VDZL-64 flaw detector is intended to trace surface defects, primarily fatigue cracks, in parts made of nonmagnetic heat-resistant materials, such as turbine blades. It reveals surface cracks as small as 0.6 X 0.15 X 0.005 mm in size. Two opposite slots of a blade are tested simultaneously. The VDZL-65 flaw detector is similar to the VDZL-64 and has the same sensitivity, but it tests simultaneously three upper slot pairs. The VDL-2M flaw detector traces cracks in heat-resistant nonmagnetic materials with 0.5--1 m/ohm (sq. mm) electric conductivity and in thin edges of enameled and bare turbine blades, nozzles, etc. It reveals cracks with a depth of 1 mm or more. The VDTs-1 flaw detector is a universal instrument which can be used for materials with an electric conductivity of 0.1--60 m/ohm (sq. mm), including ferromagnetic materials with a relatively uniform magnetic structure. It can be used for checking fins with a minimum thickness of 2 mm, fillets with a minimum radius of 2 mm, and areas around rivets, holes, bearings etc. It has a measuring mechanism and indicators similar to those of the VDL-2 detector. It can reveal cracks with a minimum length and depth of 1--3 mm and 0.2--0.3 mm, respectively, and can be used for checking coated parts without removing the protective coating. The flaw detectors reveal flaws which cannot be discovered by other means. These instruments, and especially the VDL-2M and VDTs-1 detectors, can also be successfully used to verify results obtained by other methods. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 13, 1967
- Accession Number
- AD0671587
Entities
People
- I. P. Parshin
- P. I. Beda
Organizations
- National Air and Space Intelligence Center