Effect of loading mode on the fracture toughness of a ferritic/martensitic stainless steel

Journal Article · Fri Sep 01 00:00:00 EDT 1995 · Metallurgical Transactions, A

DOI:https://doi.org/10.1007/BF02671241· OSTI ID:116040

Li, H ^[1]; Jones, R H; Gelles, D S ^[2]; Hirth, J P ^[3]

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1. Associated Western Universities, Richland, WA (United States). Northwest Div.
2. Battelle Pacific Northwest Labs., Richland, WA (United States)
3. Washington State Univ., Pullman, WA (United States). Mechanical and Materials Engineering Dept.

The critical J integrals of mode I (J{sub IC}), mixed-mode I/III (J{sub TC}), and mode III (J{sub IIIC}) were examined for a ferritic stainless steel (F-82H) at ambient temperature. A determination of J{sub TC} was made using modified compact-tension specimens. Different ratios of tension-shear stress were achieved by varying the principal axis of the crack plane between 0 and 55 deg from the load line. The value for J{sub IIIC} was determined by means of specially designed specimens. The results showed that F-82H steel had high fracture toughness. Both J{sub IC} and J{sub IIIC} were about 500 kJ/m{sup 2}, and the mode I tearing modulus (dJ{sub I}/da) was about 360 (kJ/m{sup 2})/mm. However, J{sub TC} and mixed-mode tearing modulus (dJ{sub T}/da) values varied with the crack angles and were lower than their mode I and mode III counterparts. Both the minimum J{sub TC} and dJ{sub T}/da values occurred at a crack angle between 40 and 50 deg, at which the load ratio of {sigma}{sub iii}/{sigma}{sub i} was 0.84 to 1.2. The J{sub min} was 240 kJ/m{sup 2}, and ratios of J{sub IC}/J{sub min} and J{sub IIIC}/J{sub min} were 2.1 and 1.9, respectively. The morphology of the fracture surfaces was consistent with the change in J{sub TC} and dJ{sub T}/da values. While the upper shelf-fracture toughness of F-82H depended on loading mode, the J{sub min} value remained high. Other important considerations include the effect of mixed-mode loading on the ductile-brittle-transition temperature and effects of hydrogen and irradiation on J{sub min}.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 116040
• Journal Information: Metallurgical Transactions, A, Vol. 26, Issue 9; Other Information: PBD: Sep 1995
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
70 PLASMA PHYSICS AND FUSION
IRON BASE ALLOYS
FRACTURE PROPERTIES
CHROMIUM ALLOYS
TUNGSTEN
THERMONUCLEAR REACTORS
MATERIALS
CARBON ADDITIONS
VANADIUM ADDITIONS
TANTALUM ADDITIONS
FRACTURE MECHANICS
TENSILE PROPERTIES
SHEAR PROPERTIES
CRACKS
MORPHOLOGY
DUCTILE-BRITTLE TRANSITIONS