Effect of composition on corrosion resistance of high-alloy austenitic stainless steel weld metals

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3316080· OSTI ID:6239575

Marshall, P I ^[1]; Gooch, T G ^[2]

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1. British Aerospace, Bristol (United Kingdom)
2. Welding Inst., Cambridge (United Kingdom)

The corrosion resistance of stainless steel weld metal in the ranges of 17 to 28% chromium (Cr), 6 to 60% nickel (Ni), 0 to 9% molybdenum (Mo), and 0.0 to 0.37% nitrogen (N) was examined. Critical pitting temperatures were determined in ferric chloride (FeCl[sub 3]). Passive film breakdown potentials were assessed from potentiodynamic scans in 3% sodium chloride (NaCl) at 50 C. Potentiodynamic and potentiostatic tests were carried out in 30% sulfuric acid (H[sub 2]SO[sub 4]) ar 25 C, which was representative of chloride-free acid media of low redox potential. Metallographic examination and microanalysis were conducted on the test welds. Because of segregation of alloying elements, weld metal pitting resistance always was lower than that of matching composition base steel. The difference increased with higher Cr, Mo, and N contents. Segregation also reduced resistance to general corrosion in H[sub 2]SO[sub 4], but the effect relative to the base steel was less marked than with chloride pitting. Segregation of Cr, Mo, and N in fully austenitic deposits decreased as the Ni[prime][sub eq-]Cr[prime][sub eq] ratio increased. Over the compositional range studied, weld metal pitting resistance was dependent mainly on Mo content and segregation. N had less effect than in wrought alloys. Both Mo and N enhanced weld metal corrosion resistance in H[sub 2]SO[sub 4].

• OSTI ID: 6239575
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 49:6; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CHROMIUM-NICKEL-MOLYBDENUM STEELS
CORROSION
CORROSION RESISTANCE
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HIGH ALLOY STEELS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IRON ALLOYS
IRON BASE ALLOYS
IRON CHLORIDES
IRON COMPOUNDS
JOINTS
METALLOGRAPHY
METALLURGICAL EFFECTS
METALS
MICROANALYSIS
MOLYBDENUM
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NITROGEN
NONMETALS
PITTING CORROSION
SEGREGATION
SODIUM CHLORIDES
SODIUM COMPOUNDS
STAINLESS STEELS
STEELS
SULFURIC ACID
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
WELDED JOINTS