Coated 4340 Steel

Abstract

A study was conducted to evaluate the effects of three coating systems on the mechanical property, fatigue, and stress corrosion cracking (SCC) of 4340 steel. These coating systems were electroplated cadmium and chromate passivation, cadmium with chromate primer, and cadmium, chromate primer and polyurethane topcoat. The three coating systems reduced the bending strength and hardness of the base metal, 4340 steel, in air. Their respective effects on the fatigue resistance of bare 4340 steel were similar in both of the employed environments, air and 3.5% NaCl solution. In addition, they were found to reduce the fatigue resistance of bare 4340 steel in air, but protect the substrate partly from aggressive environmental attack in 3.5% NaCl solution. The reduction of bending strength, hardness and fatigue resistance in air is attributed to hydrogen embrittlement, induced by Cd-electroplating. The SCC resistance was found to be enhanced more by each additional coating on the initial electroplated cadmium.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Aug 26, 2013
Accession Number
ADA605272

Entities

People

  • B. Pregger
  • C. Lei
  • C. Matzdorf
  • E. U. Lee
  • Michael Stanley

Organizations

  • Naval Air Warfare Center

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Chromium Compounds
  • Coatings
  • Corrosion
  • Deposition (Materials Processing)
  • Electroplating
  • Hydrogen Embrittlement
  • Materials
  • Materials Engineering
  • Mechanical Properties
  • Metals
  • Resistance
  • Stress Corrosion
  • Stress Corrosion Cracking
  • Stress Tests
  • Substrates
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Surface Coatings Technology.