Accession Number:

AD0604750

Title:

STRESS-CORROSION CRACKING OF HIGH-STRENGTH ALLOYS

Descriptive Note:

Final rept. for 1 Jul 1963-1 Jul 1964

Corporate Author:

AEROJET-GENERAL CORP AZUSA CA

Personal Author(s):

Report Date:

1964-08-01

Pagination or Media Count:

50.0

Abstract:

Susceptibility to stress-corrosion failure was found in all 18- nickel alloy heats having yield strengths from 181.5 to 232.2 ksi. Susceptibility became greater with increasing titanium content and yield strength. At a given strength level, 18-nickel maraging steel was less susceptible to failure than was H-11 steel or a hotworked die steel. Cold working of 18-nickel maraging steel before aging further reduced its susceptibility to stress-corrosion failure. Distilled water was a more severe exposure medium than 3-salt water in causing corrosion cracking, and the U-bend test was more severe than the bent-beam test - at least with regard to 18- nickel maraging steel. The 18-nickel maraging steel showed a marked increase in susceptibility to stress-corrosion cracking with an increase in environmental temperature. An inhibited epoxy coating designated as 454-1-1 was very effective in greatly delaying stress-corrosion cracking both of maraging steels and of H-11 steel. An inorganic zinc coating designed to impart cathodic protection was found to be ineffective. An electrochemical mechanism for failure of maraging steel in 3-NaCl solution was demonstrated by the preventing of stress-corrosion failure upon application of cathodic current.

Subject Categories:

  • Properties of Metals and Alloys
  • Coatings, Colorants and Finishes

Distribution Statement:

APPROVED FOR PUBLIC RELEASE