STRESS CORROSION CRACKING OF SINGLE CRYSTALS OF SOME AUSTENITIC STAINLESS STEELS

Technical Report · Sat Oct 01 04:00:00 EDT 1960

OSTI ID:4124331

Reed, R E; Paxton, H W

Crack nucleation site, orientation of the crack plane, fracture time- stress relationship, fracture surface morphology, and corrosion product composition were studied during the stress corrosinn cracking of austenitic stainless-steel single crystals. Fe--20 wt.% Cr--20 wt.% Ni, Fe--26 wt.% Cr-- 12 wt.% Ni, and commercial type 304 stainless-steel single crystals were loaded in tension in boiling 42% MgCl/sub 2/ solution. The commercial type 304 stainless steel cracked or fractured in 4 to 17 hr, the Fe--20 wt.% Cr-12 wt.% Ni in 16 to 62 hr, and the Fe--20 wt.% Cr--20 wt.a Ni in 70 to 170 hr. The crack in all three alloys nucleated from elongated pits formed when portions of slip lines were attacked by the solution. The crack plane of the Fe--20 wt.% Cr--20 wt.% Ni specimens followed the (100) plane with the highest normal stress upon it. Electron diffraction pattern made of the corrosion product from a Fe--20 wt.% Cr-- 20 wt.% Ni crack face showed that it may be a chromium-iron oxide. Colorimetric analysis of the corrosion solution showed an increase in nickel during the test. The general crack plane in type 304 and Fe--20 wt.% Cr-- l2 wt.% Ni specimens was approximately normal to the tensile axis. (auth)

• Research Organization: Carnegie Inst. of Tech., Pittsburgh
• NSA Number: NSA-15-000565
• OSTI ID: 4124331
• Report Number(s): NP-9241
• Country of Publication: United States
• Language: English

Related Subjects

AUSTENITE
CHROMIUM ALLOYS
CHROMIUM OXIDES
COLOR
CORROSION
CRACKING
CRYSTALS
DIFFRACTION
ELECTRONS
ENRICHMENT
IRON ALLOYS
IRON OXIDES
MAGNESIUM CHLORIDES
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL
NICKEL ALLOYS
PHOTOMETRY
SOLUTIONS
STAINLESS STEELS
STRESSES