THE STRESS CORROSION RESISTANCE AND FATIGUE CRACK GROWTH RATE OF A HIGH STRENGTH MARTENSITIC STAINLESS STEEL, AFC 77.
Abstract
The plane-strain corrosion threshold K sub(Iscc) and fatigue crack growth rate have been determined for a high strength martensitic stainless steel, AFC 77, in both conventionally processed and strain-aged conditions. The K sub(Iscc) (in 3.5-percent sodium chloride solution) is markedly affected by both the tempering temperature and the degree of strain aging. The highest K sub(Iscc) of 105 ksi square root of in. was obtained by tempering at 500F and the lowest K sub (Iscc) of 10 ksi square root of in. by tempering at 1100F. Retained austenite raised K sub(Iscc) at tempering temperatures up to 1000F, which was the highest tempering temperature at which austenite could be maintained. Fatigue crack growth rates in both dry air (< 10 percent relative humidity) and 3.5-percent sodium chloride solution were at a maximum for material tempered at 700F. Over the range of stress intensity studied, retained austenite reduced fatigue crack growth rate in salt solution but increased it in dry air. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0695794
Entities
People
- Donald Webster
Organizations
- Boeing Commercial Airplanes