CONTROL OF STRESS CORROSION
Interim rept. no. 2
ROCK ISLAND ARSENAL IL
Pagination or Media Count:
This study of the control of stress corrosion cracking susceptibility of steels by application of protective coatings was designed to use abrasive blasted specimens to simulate more nearly the surfaces and conditions of manufacturing operation. Bent beam speciments of 4130, 6150, and 18 nickel maraging steel were prepared at yield strength levels of 204, 231, and 316 ksi respectively for test at 75 of yield strength. Test atmospheres were outdoor, high humidity and salt spray 5, and cycles of these alternating between salt spray, humidity and air. Cycle tests produced more rapid failure than single environments. Abrasive blasting extended the time of failure as compared to non-blasted uncoated specimens. Coated specimens were electroplated with zinc, zinc phosphatized, or brushed with zinc filled paint. Specimens of 4130 steel had not failed in over a year in outdoor exposure and 6 months in high humidity. Failures were noted with all the materials in cycle tests with indication of extended time to failure as a result of using zinc filled paint.
- Properties of Metals and Alloys