Download or read book Wear and Erosion in Large Caliber Gun Barrels written by and published by . This book was released on 2004 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion in Large Gun Barrels written by NATIONAL MATERIALS ADVISORY BOARD (NAS-NAE) WASHINGTON D C. and published by . This book was released on 1975 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: The erosion of gun tubes is a very complex interdisciplinary problem involving several branches of engineering and science. Several mechanisms are responsible for this limitation to gun tube life, some of which are of thermal origin, some are mechanical and some chemical. The exact combination of these mechanisms will depend upon the following components of the gun system. (1) The gun barrel system; (2) The projectile system; (3) The charge assembly; (4) Wear reducing additives in the propellant; (5) Firing conditions. After reviewing the history of gun barrel erosion from these several points of view, possible mechanisms are discussed. Several other fields of engineering endeavors that are limited by severe wear problems are reviewed for possible sources of technology transfer. The report concludes by suggesting long and short range programs, including a number of specific ideas that should be evaluated.
Download or read book Erosion in Large Gun Barrels written by and published by National Academies. This book was released on 1975-01-15 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Confronted with problems associated with the continual upgrading of field guns, reducing the number of different items in supply and lowering overall costs, the Department of the Army has need for improved methods of reducing erosion and extending the wear life of long range cannon. The National Materials Advisory Board was asked to consider all facets of this need and to make recommendations. Erosion in Large Gun Barrels assesses the nature of the bore erosion problem; identifies fruitful areas of research; assesses the state of technology of materials and methods in areas which may become significant to gun tubes of improved performance; and suggests experimental techniques, devices, and instruments and methods of reducing data to enhance the continuing coordination of the activities of the three Services.
Download or read book The Role of Carburization in Gun Barrel Erosion and Cracking written by C. C. Morphy and published by . This book was released on 1981 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject program is part of a continuing effort to identify distinct mechanisms that contribute to gun barrel wear and erosion. The chemical effect of a carburizing atmosphere in a gun tube was the main topic for investigation in this program. Experiments were conducted in the Shock Tube Gun (STG), a ballistic compressor, designed and developed by Calspan Corporation. This facility can compress mixtures of pure gases to simulate propellant gas flow condtions and cycle time experienced in large caliber guns. Test were conducted with a mixture of argon and nitrogen to delineate the threshold of simple melting erosion which served as a chemical inert baseline. Progressive substitution of carbon monoxide for nitrogen in the mix quantified the carburizing effect as a function of CO concentration. Subsequent tests were conducted with a gas mixture containing carbon monoxide, argon and helium to measure the carburizing effect as a function of cycle time. The basic carburizing effect was observed to be a shift in the erosion threshold to less severe convective heating conditions in response to surface chemistry. The magnitude of the shift appeared to be directly proportional to heating cycle time.
Download or read book Experimental Plating of Gun Bores to Retard Erosion written by Vernon A. Lamb and published by . This book was released on 1960 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Chemistry Effects on Gun Barrel Erosion A Shock Tube Gun Investigation written by and published by . This book was released on 1982 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject program is part of a continuing effort to identify distinct mechanisms that contribute to gun barrel wear and erosion. The thermochemical effects of altering the CO/CO2 ratio of a propellant gas in a gun tube was the main topic for investigation in this program. Experiments were conducted in the Shock Tube Gun (STG), a ballistic compressor, designed and developed by Calspan Corporation. This facility can compress mixtures of pure gases to simulate propellant gas flow conditions and cycle times experienced in large caliber guns. Tests were conducted with mixture ratios of carbon monoxide and carbon dioxide that characterize the normal range of CO/CO2 ratios found in propellant gas, i.e., 2.0 to 8.1. Progressive substitution of carbon monoxide for nitrogen in the mix quantified erosion as a function of increasing Co concentration or CO/CO2 ratio. Subsequent tests were conducted with gas mixtures containing double the amount of carbon monoxide and carbon dioxide but with the same effect CO/CO2 ratio, to measure erosion as a function of absolute reactant concentration for the two gas species. The basic chemical effect was observed to be a shift in the erosion threshold to less severe convective heating conditions in response to increasing the CO/CO2 ratio above a value of 5.6. The magnitude of the shift appeared to be directly proportional to the absolute concentrations of the two reactant gases. Variation of both CO/CO2 ratio and absolute amounts of the two gases resulted in distinct changes in specimen surface characteristics, both at near threshold and above threshold flow conditions.
Download or read book Explosive Bonding written by V. D. Linse and published by . This book was released on 1967 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes basic mechanics of the process, practices of those in the field, metal combinations and configurations that have been bonded, and applications.
Download or read book Characterization of Bore Surface Layers in Gun Barrels written by and published by . This book was released on 1984 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specimens containing white layers were taken from the bore surface of the unplated and chrome plated fired gun tubes. These were examined metallographically and the presence of various white layers was established. The chemical and structural nature of these layers was determined by Auger/ESCA and x-ray diffraction techniques. The outermost white layer contained up to seven percent carbon and was identified as cementite - Fe3C. The subsequent white layers has approximately one percent carbon and were identified as high carbon austenite. The significance of these results is discussed in terms of solution and diffusion of carbon from burnt propellant are responsible for the formation of white layers and are the cause of erosion and cracking in the bore surface. During heating and cooling of fired gun barrels, stresses are generated by the differences in the coefficient of expansion and volume changes associated with cementite, austenite, and matrix metal phases. Cracks are produced in the white layer and are propagated in the substrate steel matrix. The high carbon- containing phases are lower melting than steel. These molten phases are eroded away by the sweeping hot propellant gases, thereby eroding the bore surface of the gun barrel. These and other results are discussed in terms of their effects on erosion and wear in the gun barrel bore surfaces.
Download or read book Erosion Modeling of the 120 MM M256 M829A2 Gun System written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Benet Laboratories/Software and Engineering Associates, Inc. (SEA) gun barrel erosion modeling and design code predicts wall degradation due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 120-man M256/MS29A2 gun system for ambient temperature-conditioned rounds. The A723 steel and 0.005-inch high contraction (HC) chromium plated/A723 steel wall materials are evaluated for erosion. This complex computer analysis is based on rigorously evaluated scientific theory that has been validated in the rocket community over the last forty years. Our gun erosion analysis includes the standard interior ballistics gun code (XNOVAKTC), the standard nonideal gas-wall thermochemical rocket code modified for guns (CCET). the standard mass addition boundary layer rocket code modified for guns (MABL), and the standard wall material ablation conduction erosion rocket code modified for guns (MACE). In addition, bore subsurface metallographic analysis and projectile-bore finite element analysis (ABAQUS) are considered. Our overall analysis provides wall material erosion predictions and comparisons of ablation, conduction, and erosion profiles as a function of time, travel (customer-selected 27. 61, 86, 130, and 201 inches from the rear face of the tube), and number of rounds to barrel condemnation. The 120-mm M256/M829A2 gun system prediction, with significant numbers of M829A2 rounds, agrees well with the wear and erosion pattern of retired M256 gun barrels.
Download or read book The Role of Oxygen in Gun Barrel Erosion and Cracking A Shock Tube Gun Investigation written by and published by . This book was released on 1980 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments to determine the individual contributors to gun barrel erosion in an oxidizing atmosphere were conducted in the Shock Tube Gun (STG), a ballistic compressor, designed and developed by Calspan Corporation. This facility can compress mixtures of pure gases and can generate flow conditions and cycle times similar to those experienced in large caliber guns. Tests were conducted with a mixture of argon and nitrogen to define the threshold erosion for an inert baseline. Small concentration of oxygen were substituted for nitrogen in the mix to quantify the oxidation effect. Subsequently, tests were conducted with various gas mixtures containing carbon dioxide, which dissociates to produce oxygen when compressed to high temperatures. The basic oxidation effect was observed to be nearly linear increase in erosion with oxygen concentration. A corresponding shift in the erosion threshold to less severe convective heating conditions was observed in response to surface chemistry. A similar effect was observed for carbon dioxide mixture where erosion was correlated in terms of the equilibrium concentration of oxygen at peak pressure. Surface cracking was observed and found to be most severe near the erosion threshold where the oxide layer was thickest. A white layer was observed in tests with oxygen in the absence of carbon dioxide.
Download or read book The Manufacture of Large Caliber Gun Barrels written by Stanley Wallace Shirley and published by . This book was released on 1923 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interior Ballistic Evaluation of High Flame Temperature Propellants in 20mm Ammunition and Assessment as an Erosion Test Device written by Timothy L. Brosseau and published by . This book was released on 1981 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gun barrel wear tests have uncovered the need for a small scale device to test barrel treatments like 'thick' chromium. Small caliber barrels have traditionally served this role, but results with high-firing rates used to produce measurable wear are ambiguous. An ideal erosion test device would be a small caliber gun with standard projectiles, cartridge cases and propellants which would produce wear comparable to wear in large-caliber guns. Interior ballistic tests were done with M2 or M9 propellant in place of the standard ball powder in the M55A2TP-T round to determine charge masses which would not exceed the peak chamber pressure of the reference M55A2TP-T round. The wear produced with the high-flame temperature propellants was estimated with the Frankle-Kruse empirical formula. The results showed an M9 propellant could be loaded to the same charge mass as the reference WC870 ball powder with a lower peak chamber pressure but 100 m/s higher velocity. The wear estimated for such a round is 5 micrometer/shot, comparable to wear -limited Army guns, but less than the desired 25 micrometer/shot (1 mil/shot) for an erosion test device. Hence the 20-mm gun with M9 propellant could be useful for evaluating chromium-plating for existing guns, but it has too little wear for conveniently assessing future platings and coatings.
Download or read book Investigation of Chemically Vapor Deposited Tantalum for Medium Caliber Gun Barrel Protection written by and published by . This book was released on 2008 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this SERDP-supported program (WP-1425) was to investigate the use of chemical vapor deposition (CVD) to produce high quality tantalum (Ta) coatings for wear and erosion protection of medium caliber gun barrels. In addition to offering an environmentally benign alternative to chromium (Cr) plating, this relatively low temperature process proved to provide high throughput, low cost, conformal step coverage, and coatings with desirable properties and performance.
Download or read book Ballistics 2011 written by Ernest Baker and published by DEStech Publications, Inc. This book was released on 2011-09 with total page 2230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes papers that were first presented at a September 2011 conference organized by the National Defense Industrial Association and the International Ballistics Society. This title includes a CD-ROM that displays figures and illustrations in articles in full color along with a title screen and main menu screen.
Download or read book Screening Gun Barrel Coatings Response to Combustion Gases written by and published by . This book was released on 1982 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 37-mm blowout gun, long used at BRL to study gun barrel wear, was evaluated as a screening device for testing coatings or platings on gun steel. It was shown that selection of charge mass, propellant flame temperature and rupture pressure made it possible either to remove the plating in one shot or to leave the plating virtually intact after ten shots. An erosion profile similar to plated large caliber guns was duplicated with a nozzle coated with sputtered chromium, i.e., virtually no erosion for several shots followed by flaking of the chromium from the surface. Several alloys sputtered onto nozzles and low- contraction, electroplated chromium were tested. Sputtered coatings containing tantalum warrant further investigation due to the method of the coating failure, while the low-contraction chromium did not appear any better than thicker, standard high-contraction, electroplated chromium.
Download or read book Army Science and Technology Master Plan written by United States. Department of the Army and published by . This book was released on 2001 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
