Metallographic Studies of Erosion and Thermo-Chemical Cracking of Cannon Tubes
ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE CALIBER WEAPON SYSTEMS LAB
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The characteristic erosion features of fired cannons and the closely related surface alterations on laboratory simulation samples have been examined with a variety of electron optical and other analytical techniques. The results suggest that the heat-checking pattern is caused by the large differential thermal contraction between surface austenite and subsurface tempered martensite, the deep longitudinal cracks result from liquid-solid metal embrittlement primarily by copper, and the subsurface microstructural alterations are a consequence of intense carburization by the explosion gases. The observations could provide the basis for thermomechanical modeling of the erosion and cracking of cannon tubes.
- Metallurgy and Metallography