Corrosion and Fatigue Behavior of High-Strength Steel Treated with a Zn-Alloy Thermo-diffusion Coating

Journal Article · Wed Nov 15 04:00:00 EST 2017 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-017-2969-Z· OSTI ID:22860801

Vigilante, G. N.; Cannon, J. J. ^[1]

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1. U.S. Army Armament Research Development & Engineering Center, Benét Laboratories (United States)

High and low cycle fatigue tests were conducted on high-strength steel using four-point bending. The materials tested were ASTM A723 steel in the as-machined condition, grit-blasted condition, MIL-DTL-16232 heavy manganese phosphate-coated condition, and ASTM A1059 Zn-alloy thermo-diffusion coated (Zn-TDC). The ASTM A723 steel base material exhibits a yield strength of ~1000 MPa. The effects of the surface treatments versus uncoated steel were examined. The fatigue life of the Zn-TDC specimens was generally reduced on as-coated specimens versus uncoated or phosphate-coated specimens. Several mechanisms are examined including the role of compressive residual stress relief with the Zn-TDC process as well as fatigue crack initiation from the hardened Zn-Fe alloy surface layer produced in the gas-metal reaction. Additionally, the effects of corrosion pitting on the fatigue life of coated specimens are explored as the Zn-TDC specimens exhibit significantly improved corrosion resistance over phosphate-coated and oiled specimens.

• OSTI ID: 22860801
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 11 Vol. 26; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORROSION
CORROSION RESISTANCE
CRACK PROPAGATION
DIFFUSION COATING
DIFFUSION COATINGS
LAYERS
MANGANESE PHOSPHATES
PRESSURE RANGE GIGA PA
RESIDUAL STRESSES
SURFACE TREATMENTS
SURFACES
ZINC ALLOYS