Influence of deformation-induced martensite on fatigue crack propagation in 304-type steels

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02647310· OSTI ID:7126974

Mei, Z; Morris, Jr, J W ^[1]

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1. Lawrence Berkeley Lab., CA (United States). Center for Advanced Materials Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

This research reports an investigation into the influence of mechanically induced martensitic transformation on the rate of fatigue crack growth in 304-type austenitic stainless steels. Two steels of different composition, 304L and 304LN, were used to test the influence of composition; two test temperatures, 298 and 77 K, were used to study the influence of test temperature; and various load ratios were used to determine the influence of the mean stress. It was found that decreasing the mechanical stability of the austenite by changing composition or lowering temperature reduces the fatigue crack growth rate and increases the threshold stress intensity for crack growth. However, this beneficial effect diminishes as the load ratio increases, even though increasing the load ratio increases the extent of the martensite transformation. Several mechanisms that may influence this behavior are discussed, including the perturbation of the crack tip stress field, crack deflection, work hardening, and the relative brittleness of the transformed material. The perturbation of the stress field seems to be the most important; by modifying previous models, the authors develop a quantitative analysis of the crack growth rate that provides a reasonable fit to the experimental results.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7126974
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 21; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
AUSTENITIC STEELS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
CRACK PROPAGATION
DATA
EXPERIMENTAL DATA
FATIGUE
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
LOW CA
MATERIALS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
NICKEL ALLOYS
NUMERICAL DATA
PHASE TRANSFORMATIONS
STAINLESS STEEL-304
STAINLESS STEEL-304L
STAINLESS STEELS
STEEL-CR19NI10
STEEL-CR19NI10-L
STEELS
STRESS INTENSITY FACTORS
TENSILE PROPERTIES