Acoustic emission for detecting crack initiation in stainless steel

Technical Report · Tue May 01 00:00:00 EDT 1990

OSTI ID:7123230

Jones, R H; Friesel, M A ^[1]

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1. Pacific Northwest Lab., Richland, WA (USA)

Acoustic emission (AE) has been evaluated as a technique for detecting the growth of short cracks. The purpose of this work was to assess the feasibility of detecting intergranular stress-corrosion cracking (IGSCC) initiation with acoustic emission and to evaluate the minimum crack length detectable with AE. Acoustic emission offers potential advantages over other techniques for detecting crack initiation and the early stages of crack growth: dynamic real-time measurements and remote monitoring are possible, the technique is passive and nonintrusive, it is not necessary to know the crack location, the crack can be located by detector arrays, and the technique is interfaceable with automatic data acquisition equipment and is suitable for long-term monitoring. It was demonstrated in this program that AE was capable of detecting early stages of crack growth in Type 304 SS. Intergranular stress corrosion cracks of 200 to 300 {mu}m in length and 100 to 200 {mu}m in depth were detectable with AE. The results were similar for material with a high and low degree of sensitization in both Na{sub 2}S{sub 2}O{sub 3} and NaCl environments. The results of this research program demonstrate the usefulness of AE in detecting early stages of crack growth. Further evaluation of this technique is recommended with evaluation of transgranular crack initiation and intergranular stress corrosion crack initiation in other materials such as Inconel 600 (IN 600), welded samples of Type 304 SS and scaleup to pipe studies. There is also evidence that the AE technique has not been fully optimized and that improvements in signal-to-noise ratios and signal amplification are possible.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (USA); Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: EPRI
• OSTI ID: 7123230
• Report Number(s): EPRI-NP-6844
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
STAINLESS STEEL-304
ACOUSTIC EMISSION TESTING
CRACKS
INCONEL 600
INTERGRANULAR CORROSION
SODIUM CHLORIDES
SODIUM SULFATES
STRESS CORROSION
ACOUSTIC TESTING
ALKALI METAL COMPOUNDS
ALLOY-NI76CR15FE8
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
AUSTENITIC STEELS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
HALIDES
HALOGEN COMPOUNDS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
INCONEL ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MATERIALS TESTING
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIMONIC
NONDESTRUCTIVE TESTING
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
STAINLESS STEELS
STEEL-CR19NI10
STEELS
SULFATES
SULFUR COMPOUNDS
TESTING
TITANIU
TITANIUM ADDITIONS
360105* - Metals & Alloys- Corrosion & Erosion
420500 - Engineering- Materials Testing