Download or read book Physicochemical Aspects of Gun Barrel Erosion and Its Control written by and published by . This book was released on 1975 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gun tube erosion can be defined as the bore surface damage and bore enlargement caused by firing, which can lead to loss in accuracy and the effectiveness of the weapon. It is one of the two major factors on the basis of which gun tubes are condemned; the other factor being fatigue life, Erosion is a complex phenomenon resulting from the interaction of propellant gases and the projectile with the surface of the bore. The bore surface is exposed for a short time to temperature approaching the melting point of steel, pressures as high as 50,000 psi, reactive atmosphere composed of CO, CO2, H2O, H2, N2, and numerous other identified and unidentified constituents. Superimposed on these conditions are the high velocity of gases and swaging action of the projectile rotating band. It is the objective of this presentation to review the physicochemical processes involved in erosion and indicate some critical areas which need further investigation. Also, various efforts to control erosion in barrels will be briefly discussed.

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 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 Government Reports Annual Index written by and published by . This book was released on 1981 with total page 1194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Erosion and Its Control written by and published by . This book was released on 1982 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gun erosion is a complicated process which involves a number of interrelated factors. There is general agreement that erosion is a function of bore temperature but this does not eliminate controversy about its causes or the relative importance of different factors. The three effects involved in gun erosion are thermal, chemical, and mechanical. In the case of the most important erosion, that of steel bores at the origin-of-rifling, the chief factor is probably thermal. However, no matter what the specific mechanism of erosion, it is a function of the rate of heat transferred to the bore. It can only be controlled by making the steel bore more resistant to temperature by coating it with a layer of another material or by lowering the rate of heat transfer from the propellant gases. (Author).

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 Orgies Continentales written by and published by . This book was released on 1904 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Erosion in Large Gun Barrels written by and published by . This book was released on 1975 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1976 with total page 1204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1976 with total page 1756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 30 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 First Computer Code for Predicting Thermochemical Erosion in Gun Barrels written by and published by . This book was released on 1996 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: An update is provided for the previously-presented gun barrel thermochemical erosion modeling code. This code addresses wall degradations due to transformations, chemical reactions, and cracking. As a predictive tool, it provides analysis and design information that is either unattainable or expensive by experiment. Single- or multiple-shot comparisons can be made of either the same gun wall material for different rounds, or different gun wall materials for the same round., this complex computer analysis is based on rigorous scientific thermochemical erosion considerations that have been validated in the reentry nosetip and rocket nozzle/chamber community over the last forty years. A gun system example is used to illustrate the five module analyses for chromium and gun steel wall materials for the same round. The first two modules include the somewhat modified standard gun community XNOVAKTC interior ballistics and BLAKE nonideal gas thermochemical equilibrium codes. The last three modules, significantly modified for gun barrels, include the standard rocket community two-dimensional kinetics!mass addition boundary layer (TDK/MABL), gas-wall thermochemistry TDK/CBT), and wall material ablation conduction erosion (MACE) codes. These five analyses provide thermochemical ablation, conduction, and erosion profiles for each material as a function of time, travel, and rounds. For the gun system example, at two axial positions, with cold and hot firing rates. predictions of rounds required to achieve 0.040-inch wall loss are made for cracked and uncracked 0.005-inch chromium plated A723 steel and A723 steel alone. Thermochemical erosion increases by a factor of about 2.0 from cracked chromium plated A723 steel to A723 steel alone. For a given%wall, thermochemical erosion decreases by a factor of 1.4 from the hot to the cold firing rates.

Download or read book A New Additive for Reducing Gun Barrel Erosion written by Jean-Paul Picard and published by . This book was released on 1968 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1986 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Process Engineering and Industrial Management written by Jean-Pierre Dal Pont and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Process Engineering, the science and art of transforming raw materials and energy into a vast array of commercial materials, was conceived at the end of the 19th Century. Its history in the role of the Process Industries has been quite honorable, and techniques and products have contributed to improve health, welfare and quality of life. Today, industrial enterprises, which are still a major source of wealth, have to deal with new challenges in a global world. They need to reconsider their strategy taking into account environmental constraints, social requirements, profit, competition, and resource depletion. “Systems thinking” is a prerequisite from process development at the lab level to good project management. New manufacturing concepts have to be considered, taking into account LCA, supply chain management, recycling, plant flexibility, continuous development, process intensification and innovation. This book combines experience from academia and industry in the field of industrialization, i.e. in all processes involved in the conversion of research into successful operations. Enterprises are facing major challenges in a world of fierce competition and globalization. Process engineering techniques provide Process Industries with the necessary tools to cope with these issues. The chapters of this book give a new approach to the management of technology, projects and manufacturing. Contents Part 1: The Company as of Today 1. The Industrial Company: its Purpose, History, Context, and its Tomorrow?, Jean-Pierre Dal Pont. 2. The Two Modes of Operation of the Company – Operational and Entrepreneurial, Jean-Pierre Dal Pont. 3. The Strategic Management of the Company: Industrial Aspects, Jean-Pierre Dal Pont. Part 2: Process Development and Industrialization 4. Chemical Engineering and Process Engineering, Jean-Pierre Dal Pont. 5. Foundations of Process Industrialization, Jean-François Joly. 6. The Industrialization Process: Preliminary Projects, Jean-Pierre Dal Pont and Michel Royer. 7. Lifecycle Analysis and Eco-Design: Innovation Tools for Sustainable Industrial Chemistry, Sylvain Caillol. 8. Methods for Design and Evaluation of Sustainable Processes and Industrial Systems, Catherine Azzaro-Pantel. 9. Project Management Techniques: Engineering, Jean-Pierre Dal Pont. Part 3: The Necessary Adaptation of the Company for the Future 10. Japanese Methods, Jean-Pierre Dal Pont. 11. Innovation in Chemical Engineering Industries, Oliver Potier and Mauricio Camargo. 12. The Place of Intensified Processes in the Plant of the Future, Laurent Falk. 13. Change Management, Jean-Pierre Dal Pont. 14. The Plant of the Future, Jean-Pierre Dal Pont.

Download or read book Agricultural Practices and Water Quality written by Ted L. Willrich and published by . This book was released on 1971 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: SEDIMENT AS A WATER POLLUTANT; PLANT NUTRIENTS AS WATER POLLUTANTS; PESTICIDES AS WATER POLLUTANTS; ANIMAL WASTES AS WATER POLLUTANTS; AGRICULTURAL POLLUTION IMPLICATIONS; AGRICULTURE'S INVOLVEMENT IN POLLUTED AND CLEAN WATER.