Corrosion Fatigue Testing of Propeller Alloys

Abstract

The test program is underway to obtain new S-n data at several mean stress level for ABS bronzes type 2, 4 and 5 plus type CA6NM stainless steel. The results at 100 megacycles will be used to compare the alloys through the use of modified Goodman diagrams. The test 200 cpm.in the sea water and extending up to 100 mc (nearly one year) duration shall provide a higher ratio of corrosion damage to fatigue damage than that obtained in short-term high-frequency testing. Heavy section castings to approximate the root section of a propeller blade are the source of material for Krouse type fatigue specimens.