Stress corrosion cracking and hydrogen embrittlement of ferritic stainless steels: effects of thermomechanical treatments

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6737871

Iyer, R N

The influence of thermomechanical treatments on the stress corrosion crack initiation and hydrogen assisted crack growth of 26 Cr-1Mo alloys in boiling 42% LiCl solutions and 5% H/sub 2/SO/sub 4/ solutions was investigated using a uniaxial constant load fixture. Annealing at temperatures where only recovery processes operate, reduces the susceptibility of prestrained low interstitial 26 Cr-1Mo alloy (E-Brite) to SCC in boiling chloride solutions. Both slip-step height and density, which are the major parameters controlling the breakdown of protective films in these alloys, are reduced substantially by annealing near 300/sup 0/C for 1 hour. Continuous exposure of unfilmed metal to the progressive environment is provided during SCC due to creep; this causes reduction in overall repassivation rate. Grain coarsening and prestraining operations result in larger slip step height and density due to increase in dislocation density. Crack propagation potential for as-received (mill-annealed) E-Brite during SCC in boiling chloride solution is the protection potential for the localized corrosion. Crack growth in SCC of these ferritic stainless steels is by the hydrogen embrittlement mechanism.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA)
• OSTI ID: 6737871
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
ANNEALING
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CORROSION
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
CRACKS
EMBRITTLEMENT
FERRITIC STEELS
HALIDES
HALOGEN COMPOUNDS
HEAT TREATMENTS
HIGH TEMPERATURE
HYDROGEN COMPOUNDS
HYDROGEN EMBRITTLEMENT
INORGANIC ACIDS
IRON ALLOYS
IRON BASE ALLOYS
LITHIUM CHLORIDES
LITHIUM COMPOUNDS
LITHIUM HALIDES
MOLYBDENUM ALLOYS
STAINLESS STEELS
STEELS
STRESS CORROSION
SULFURIC ACID