Research survey and measurement of environmental factors for preserving and storing scud missile at brigade 490

verage temperature is 26,3  C. These are two factors that create favorable conditions for the process of corrosion and destruction of the materials. In the environment, there are also corrosive gases with relatively high content such as CO: 850 g/m3, NO2: 30.5 g/m 3 , SO2 gas content: 81.3 g/m 3 and Cl2 gas: 0.3 g/m 3 . Keywords: Environmental factors; Scud missile preservation; Corrosion. 1. INTRODUCTION The Scud A missile complex (NATO called SS-1b) was designed and put into used by the Soviet Union in 1957 based on the German V2 missile, the missile uses liquid fuel engine, the navigation system independent inertia, self-destructing warhead system. This missile system is used and preserved by the military from the 1970s, 1980 to the present. The missile complex is made of different materials: metals, polymers, composite,... so it is greatly influenced by environmental conditions of exploitation, use and preservation. The missile's components are made of alloys, aluminum, steel, titanium, copper,... [1] will be greatly affected by environmental factors such as temperature, humidity and corrosive gases such as CO, NO2, Cl2, [2-5] lead to corrosion causing damage and degradation of the missile. The other components of the missile are made of non-metallic materials such as rubber, plastic, grease or rocket fuel,... These materials are also strongly affected by the surrounding environment. Causes aging of polymer materials. The aging process of polymer materials is due to the impact of solar radiation and oxygen in the environment. In radiation rays, ultraviolet rays have a very strong influence, especially for details and products that are directly illuminated for a long time. Oxygen also causes strong aging phenomenon of polymer materials whether in dry environment or high humidity environment, especially atomic oxygen or ozone. These reasons also make the life of the missile combination reduced. The impact of the environment on the types of materials, typical details of the Scud missile complex such as metals, polymers, electrical - electronic control equipment, grease and fuel, propellants, explosives,... is the sum of many factors. Therefore, the problem of researching, surveying and measuring environmental factors between this particular weapon, such as temperature, humidity, the content of gases that cause corrosion and material destruction has practical meaning in order to evaluate the storage environment as well as propose optimal plans in the process of storing and preserving this particular weapon. 2. EXPERIMENTS AND METHODS 2.1. Materials and equipments 2.1.1. Materials - Moisture indicator paper, Vietnam - Phenolphthalenine, H2SO4, NaCl, NaOH, HCl, EDTA, standard pH tube, filter paper, HNO3, toluene, ethyl acetate, China. 2.1.2. Equipments - Handy air Sampler Kimoto, model HS - 7, Japan Kỹ thuật điều khiển & Điện tử 86 P. N. Hoan, , P. X. Thao, “Research survey and measurement Scud missile at brigade 490.” - Toxic gas monitor, model SC - 90, Riken, Japan - Walklab digital lux meter, Germany - Multi function environmental meter, model LM - 8000, LUTRON, Taiwan - OLDHAM MC2100 Gas monitor, France. 3. RESULTS AND DISCUSSION 3.1. Results of the survey on the air and the content of corrosive gases at Brigade 490 The main cause of damage and degradation to weapons and technical equipment stored in insulation warehouses is mainly caused by the atmospheric environment. In addition, pollutants such as NOx, SOx, CO,... in the process of industrial development and human activities in our country also contribute to the speed of destruction and degradation of weapons and technical equipment. In order to have the assessment of the destruction and degradation of the material in the atmospheric environment, we conducted air measurements in the field in different areas in Brigade 490. Measured results environmental factors (measured time 2014) as well as the content of polluting gases are presented in the following tables 1 and 2: Table 1. Environmental factors and gas content at the site Scud missile storage. Parameters Measure Test methods Result (Area K1) QCVN 05,06:2009/BTNMT Temperature C TCVN 5508-1991 33,1 - Atmospheric moisture % TCVN 5508-1991 76,4 - Wind speed m/s TCVN 5508-1991 0,5 - Sunlight Lux TCVN 5176:1990 210 - CO g/m3 TCVN 7725:2007 850 30000 (*) NO2 g/m 3 TCVN 6138:1996 30,5 200 (*) SO2 g/m 3 TCVN 7726:2007 79 350 (*) O3 g/m 3 TCVN 7171:2002 kpht 180 (*) Cl2 g/m 3 TCVN 7744:2003 0,2 100 (**) H2S g/m 3 ASA 701r2 khpt 42 (**) Notes: "-": Not specified kpht: Not detected (*) QCVN 05: 2009/BTNMT: National technical regulation on ambient air quality (average 1 hour). (**) QCVN 06: 2009/BTNMT: National technical regulation on some hazardous substances in ambient air (average 1 hour). Area K1: At storage bag testing site. Table 2. Environmental factors and gas content in the front position of the missile maintenance and repair station. Parameters Measure Test methods Results (Area K2) QCVN 05,06:2009/BTNMT Temperature C TCVN 5508-1991 30,5 - Atmospheric moiture % TCVN 5508-1991 80,2 - Wind speed m/s TCVN 5508-1991 0,3 - Sunlight Lux TCVN 5176:1990 198 - CO g/m3 TCVN 7725:2007 900 30000 (*) NO2 g/m 3 TCVN 6138:1996 40 200 (*) SO2 g/m 3 TCVN 7726:2007 81,3 350 (*) O3 g/m 3 TCVN 7171:2002 kpht 180 (*) Nghiên cứu khoa học công nghệ Tạp chí Nghiên cứu KH&CN quân sự, Số 70, 12 - 2020 87 Cl2 g/m 3 TCVN 7744:2003 0,3 100 (**) H2S g/m 3 ASA 701r2 kpht 42 (**) Notes: "-": Not specified kpht: Not detected (*) QCVN 05: 2009/BTNMT: National technical regulation on ambient air quality (average 1 hour). (**) QCVN 06: 2009/BTNMT: National technical regulation on some hazardous substances in ambient air (average 1 hour). Area K2: At the position in front of the missile maintenance station. From the measurement results at different locations at the missile maintenance station of Brigade 490 shows that environmental factors such as humidity, temperature, wind speed, sunlight,... at locations the field is different, the humidity is over 75%, the temperature is over 29  C, which is the favorable condition for the corrosion and degradation of easily destroyed materials in the missile complex. When high humidity in the air leads to moisture condensation on the surface of metal materials, it will make up an electrolyte solution film, the rate of electrochemical corrosion will occur strongly and mainly destroy metals constituting the equipment, weapons and technical equipment. In addition, the results of the measurement of corrosive gases in the atmospheric environment at different locations of the Brigade 490 maintenance station showed that gases such as CO, NO2, SO3, and Cl2 appeared with have content relatively high. The gases contributes to faster corrosion and faster destruction of materials in the engineering weapon complex (Scud missiles), leading to the preservation of weapon has many difficulties. 3.2. Results of collection of environmental factors in the stationed area of Brigade 490 from data of the National Center for Hydro-Meteorological Forecasting From the measurement results of the surrounding environment factors, in storage warehouses at different locations of the missile maintenance Brigade 490 at a certain time of the year, the environmental factors are favorable corrosion occurs. Done to get a comprehensive and complete assessment of environmental factors that directly affect the storage and preservation of technical weapons in general or missiles in particular, such as: seasonal changes in temperature, average annual rainfall,... we have collected environmental data from the monitoring stations in the Army stationed area 490 from January 1, 2009 to June 25, 2014. From the database of the National Center for Hydro-Meteorological Forecasting, the results are presented in the following table 3 Table 3. Meteorological and hydrological monitoring data at Chi Linh - Hai Duong. Parameters Measure 2009 2010 2011 2012 2013 6/2014 Annual average rainfall mm 106,4 142,15 118,02 124.84 139,96 57,42 Annual average lowest temperature C 21,6 21,7 20,2 21,3 21,2 20,1 Annual average highest temperature C 28,2 27,8 26,5 27,3 27,5 26,3 Annual average humidity % 93,25 82,5 82,2 84,9 83,2 85 Total average annual sunshine hours hour 127 110,8 107,9 97,5 112,3 - Note: Data source is from the data warehouse of the National Center for Hydro- Meteorological Forecasting From the data in table 3, it shows that the main climatic factors such as humidity and temperature have caused many difficulties in the preservation and use of the Scud missile complex in the stationed area of brigade 490 (Chi Linh - Hai Duong) are relatively high such as: - The annual average rainfall in the area stationed of the Brigade 490 is relatively high > 100 mm/year. - The annual average humidity in Chi Linh - Hai Duong is greater than 80%, this is the Kỹ thuật điều khiển & Điện tử 88 P. N. Hoan, , P. X. Thao, “Research survey and measurement Scud missile at brigade 490.” cause of condensation water on the surface of the materials, creating favorable conditions for the eating process. - The annual average maximum temperature in Chi Linh - Hai Duong is all greater than 26.3  C. The total number of common sunny hours is 100 hours/year. This is also the reason that accelerates the corrosion and destruction of the material. 4. CONCLUSION From the results obtained during the measurement of climatic factors in the field as well as climatic factors from the database of the National Center for Hydro-Meteorological Forecasting, it shows the environment in the area stationed of the Brigade 490 has the following characteristics: - The annual average humidity is greater than 80%, the average temperature is 26.3  C. These are two factors that create favorable conditions for the corrosion and destruction of materials. - In the air environment, there appear corrosive gases with relatively high contents such as: CO content: 850 to 900 g/m3, NO2 gas content: 30.5 to 40 g/m 3 , SO2 gas content: 79 to 81.3 g/m3, Cl2 gas: 0.2 to 0.3 g/m 3 . These gases contribute to speed up the corrosion process, the destruction of materials leading to the rapidly degrading of weapons and technical equipment. Therefore, the issue of finding out how to preserve this special weapon in accordance with the local climatic conditions is a necessary issue in order to increase the shelf life of this weapon. REFERENCES [1]. Nguyen Hoa Thinh, Hoang Xuan Luong, Nguyen Duc Cuong, Trinh Hong Anh, Nguyen Minh Tuan. “Structure and flight tool durability calculation”, Science and Technology Publishing House, Hanoi, (2005). [2]. D. A. Jones. “Principles and prevention of corrosion”, Macmillan Publishing Company (1991). [3]. Christofer Leygraf and Thomas Graedel, (2000). “Atmospheric Corrosion”, Wiley InterScience, A John Wiley & Sons, Inc., Publication. [4]. Le Dang anh, Nguyen Dinh, “Tropical climate and the maintenance of machinery and equipment”, (1972). [5]. W. H. Vernon. Tran. “Faraday Soc.”, 23, p.1668 - 1671 (1935). TÓM TẮT KHẢO SÁT, ĐO ĐẠC CÁC YẾU TỐ MÔI TRƯỜNG CẤT GIỮ TÊN LỬA SCUD TẠI LỮ ĐOÀN 490 Bài báo trình bày một số kết quả đo đạc, khảo sát điều kiện môi trường tại khu vực niêm cất bảo quả tên lửa Scud. Kết quả thu thập số liệu cho thấy, độ ẩm trung bình hàng năm lớn hơn 80%, nhiệt độ trung bình hàng năm cao nhất đạt 26,3 C đây là hai yếu tố tạo điều kiện thuận lợi cho quá trình ăn mòn và phá hủy vật liệu. Trong môi trường còn xuất hiện các loại khí gây ăn mòn có hàm lượng tương đối cao như CO: 850 g/m3, NO2: 30,5 g/m3, hàm lượng khí SO2: 81,3 g/m 3 và khí Cl2: 0,3 g/m 3 . Từ khóa: Yếu tố môi trường; Bảo quản tên lửa Scud; Ăn mòn. Received 23 rd October 2020 Revised 09 th November 2020 Published 14 th December 2020 Author affiliations: 1 Institute of Chemistryl and Materials/Academy of Military Science and Technology. * Corresponding author: nhuhoan121702@gmail.com.