Accession Number : ADA116284

Title :   Characterization of 'White Layer' and Chrome Plating on Fired Cannon and on Laboratory Simulation Samples.

Descriptive Note : Final rept. Jan 81-Jan 82,

Corporate Author : UNITED STATES STEEL CORP MONROEVILLE PA RESEARCH LAB

Personal Author(s) : Fisher,R M ; Szirmae,A

PDF Url : ADA116284

Report Date : Jun 1982

Pagination or Media Count : 55

Abstract : This work confirms that the effect of exposure of 4340 steel cannon tubes to firing is the formation of Fe3C and 1% C-austenite on the surface. The stress generated by the explosion results in the formation of rather uniform networks of shallow and deep cracks. Particular attention was given to the structure of these cracks because they contained TiO2 (sometimes added to the charge), Cu, S, and Al. Examination of the microstructure of electrodeposited chromium revealed a strong dependence of grain structure on plating conditions. The void space between the aligned cylindrical grains is probably responsible for the high tensile stresses in chrome plating and the propensity for severe cracking.

Descriptors :   *Gun barrels, *Deposits, *Steel, *Chromizing, Boreholes, Guns, Wear, Surfaces, Austenite, Tensile Stress, Electrodeposition, Chromium, Plating, Microstructure, Cracks, Titanium oxides, Grain structures(Metallurgy), Cylindrical bodies, Exposure(General)

Subject Categories : Fabrication Metallurgy
      Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE