Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report

Rapp, R A

doi:10.2172/663568

Title: Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report

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Abstract

With the aid of computer-assisted calculations of the equilibrium vapor pressures in halide-activated cementation packs, processing conditions have been identified and experimentally verified for the codeposition of two or more alloying elements in a diffusion coating on a variety of steels and refractory metal alloys. A new comprehensive theory to treat the multi-component thermodynamic equilibria in the gas phase for several coexisting solid phases was developed and used. Many different processes to deposit various types of coatings on several types of steels were developed: Cr-Si codeposition for low- or medium-carbon steels, Cr-Al codeposition on low-carbon steels to yield either a Kanthal-type composition (Fe-25Cr-4Al in wt.%) or else a (Fe, Cr){sub 3}Al surface composition. An Fe{sub 3}Al substrate was aluminized to achieve an FeAl surface composition, and boron was also added to ductilize the coating. The developmental Cr-lean ORNL alloys with exceptional creep resistance were Cr-Al coated to achieve excellent oxidation resistance. Alloy wires of Ni-base were aluminized to provide an average composition of Ni{sub 3}Al for use as welding rods. Several different refractory metal alloys based on Cr-Cr{sub 2}Nb have been silicided, also with germanium additions, to provide excellent oxidation resistance. A couple of developmental Cr-Zr alloys were similarly coatedmore » and tested.« less

Authors:

Rapp, R A ^[1]

Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

Publication Date:: Tue Mar 10 00:00:00 EST 1998

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ohio State Univ., Dept. of Materials Science and Engineering, Columbus, OH (United States)

Sponsoring Org.:: USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)

OSTI Identifier:: 663568

Report Number(s):: ORNL/Sub-87-SB1154/04
ON: DE98006093; TRN: AHC29818%%406

DOE Contract Number:: AC05-96OR22464

Resource Type:: Technical Report

Resource Relation:: Other Information: PBD: 10 Mar 1998

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; PROGRESS REPORT; CORROSION PROTECTION; STEELS; SURFACE COATING; HALIDES; DIFFUSION; REFRACTORY METALS; SEAWATER

Citation Formats


                    Rapp, R A. Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report.  United States: N. p., 1998. 
        Web.  doi:10.2172/663568.

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                    Rapp, R A. Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report.  United States.  https://doi.org/10.2172/663568

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                    Rapp, R A. 1998.  
        "Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report".  United States.  https://doi.org/10.2172/663568.  https://www.osti.gov/servlets/purl/663568.

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@article{osti_663568,

  title        = {Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report},

  author       = {Rapp, R A},

  abstractNote = {With the aid of computer-assisted calculations of the equilibrium vapor pressures in halide-activated cementation packs, processing conditions have been identified and experimentally verified for the codeposition of two or more alloying elements in a diffusion coating on a variety of steels and refractory metal alloys. A new comprehensive theory to treat the multi-component thermodynamic equilibria in the gas phase for several coexisting solid phases was developed and used. Many different processes to deposit various types of coatings on several types of steels were developed: Cr-Si codeposition for low- or medium-carbon steels, Cr-Al codeposition on low-carbon steels to yield either a Kanthal-type composition (Fe-25Cr-4Al in wt.%) or else a (Fe, Cr){sub 3}Al surface composition. An Fe{sub 3}Al substrate was aluminized to achieve an FeAl surface composition, and boron was also added to ductilize the coating. The developmental Cr-lean ORNL alloys with exceptional creep resistance were Cr-Al coated to achieve excellent oxidation resistance. Alloy wires of Ni-base were aluminized to provide an average composition of Ni{sub 3}Al for use as welding rods. Several different refractory metal alloys based on Cr-Cr{sub 2}Nb have been silicided, also with germanium additions, to provide excellent oxidation resistance. A couple of developmental Cr-Zr alloys were similarly coated and tested.},

  doi          = {10.2172/663568},

  url          = {https://www.osti.gov/biblio/663568},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Tue Mar 10 00:00:00 EST 1998},

  month        = {Tue Mar 10 00:00:00 EST 1998}

}

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