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6ТЕХНИЧЕСКИЕ НАУКИ
MANUFACTURING OF FLANGE BY COLD FORMING USING DIES
Abdullah Mohammed Najeeb
Lecturer, Mechanical Engineering Department, College of Engineering University Of Mosul, Mosul, Iraq
ПРОИЗВОДСТВО ФЛАНЦЕВОЙ ПОКОВОК ХОЛОДНОЙ ШТАМПОВКИ С ИЗПОЛЬЗОВАНИЕМ МАТРИЦЕЙ Абдуллах Мохаммед Наджиб, Преподаватель, Кафедра Машиностроения, Инженерный колледж, Мосульский университет, Мосул, Ирак
ABSTRACT
The paper includes study of the manufacturing process of the flange using dies, worked laboratory model of die implemented on lead metal cold forming. Results indicate that the process of formation is influenced by shape of work piece with fixed volume and the type pressing. It is noted that the process of pressing flange at one stage needs high stress regardless of shape of resulting model. While in case of preliminary pressing of the piece work in the first stage improves the mechanical properties of the metal and thus facilitates the final deformation process within the die with less stress and better flow of the metal inside the die.
Keywords: flange, dies, cold forming
АННОТАЦИЯ
Статья включает в себя изучение производственного процесса фланцевой поковки с использованием холодной штамповки, работал лабораторной модели фланец реализованы на формирование металлического свинца холодно. Результаты показывают, что процесс формирования зависит от формы заготовки с фиксированным объемом и типом прессования. Следует отметить, что процесс прессования фланец на одном этапе необходим высокий напряжение, независимо от формы приводит модель. В то время как в случае предварительное прессование частей работы на первой этапе улучшает механические свойства металла и, таким образом, облегчает окончательный процесс деформации внутри матрицы с меньшим напряжением и лучшего течения металла внутри матрицы.
Ключевые слова: фланец, матрица, холодной штамповки
Introduction
Mechanical forming operations include all forming operations that take place on the metals and alloys in solid case without any melted. All these processes go on under the influence of mechanical forces by using special equipment and hardware that are securing these powers and bring about the change required in the forms or metal bodies, alloys that can performed these operations either cold or hot[1]. The ability of metals and alloys to any change in the shape by effect of mechanical forces related with structure and the crystal lattice of the metal. So there is considerable variation in ability of metals or alloys to mechanical forming [2]. Mechanical forming performed under forces or stresses exceed yield strength of metals or alloys that any change or deformity in the form will be elasticity with accompanied by usually changes in the mechanical and physical properties of metals for deformed metal [3].
The purpose of this paper is obtain a final product of the flange free from defects in the formation of die, minimal stress of machine, and minimal losses for the metal user.
The experimental work
Practical part of the research is containing manufacturing flange of real dimensions, due to the fact that the machines pressing available with a few loads the work of laboratory model dimensions will be mini and performed on lead metal by cold forming, which lead to form at
temperature less than the recrystallization temperature. In order to get the product it needs design and manufacturing of metal die according to the required measurements of the metal deformed, and performing the metal experiments by pressing metal in two stages to formation the metal within the die with less defects.
Amount of lead metal prepared, melted, and poured in a special die with its two halves in order to get a cylindrical piece of 20 mm diameter and 60 mm height to perform experiments for manufacturing flange by cold forming in the die as shown in figure (1).
Punches and dies used for manufacturing of forged parts as in figure (2). The dies manufactured with the dimensions as marked in high-resolution operating machines made of stainless steel metal and annealed by heat treatment.
For calculating the metal volume used in the pressing process mechanical AutoCAD program implemented depending on the volume of the internal die product, which represents the volume of the metal pressing as shown in figure (3).
Hardening process for the die done by electric furnace by placing parts of the die in furnace with temperature of 870 oC inside the furnace for an hour time and then the process of hardening carried out by oil. Figure (4) illustrates the stages of hardening process used in the study.
Figure 1. Die preparation sample
Figure 2. Parts of dies and assembling
Tamp'C
Figure 3. The method of calculating the sample volume used for pressing
Pressing process has been done using computerized hydraulic press machine with 100 tons ability as shown in figure (5) with accessories of measuring instruments for loading and displacement. Relationship between loading and displacement during the pressing process recorded.
Figure 4. Stages of hardening process
The initial pressing stage includes pressing the sample (20 mm diameter, 27 mm height) by hydraulic machine to different heights to get different diameters as shown in figure (6) to performing practical experiments for pressing flange in the second stage and to get the product less defects.
Figure 5. Hydraulic pressing machine and accessories
After the initial pressing process stage, the resulting sample is placed in the middle of the die in the lip region and closing the mold then the punch inserted to the die. The assembled die is placed between the lower part and moving upper part of the machine until it constants the punch. Then the applying process begins until the punch reaches the rated limit that indicated in the punch circular shaped. Figure 7
illustrates the processing of the work piece inside the die and the pressing process.
Results pressing operations
The process of flange pressing carried out in four different forms of the work piece (Figure 8) inside of the manufacturing die. Final results shown in table (1), which includes applied load (KN) and the displacement of the press (mm).
Figure 7. Preparing the work piece inside the die and the process of pressing
Figure 8. forms of work pieces Results of pressing stages flange
Table 1
No. of Sample Initial Stage Pressing Final Stage Pressing
Displacement(mm) Load(KN) Displacement(mm) Load(KN)
1 0.0 0.0 21.7 234.5
2 8.0 25.2 25.2 195.0
3 9.9 26.2 22.2 197.4
4 12.5 28.5 21.5 115.8
Discussion
Four models of flange prepared practically, each model has been formed in a different way, so different relationship between load and displacement obtained.
The first model was formed directly in the die with one stage and without initial pressing of work piece as shown in figure 8. Load applying and displacement measuring devices attached to the pressing machine recorded the relation shown in figure (9). In which load increases continuously with displacement of the punch via good quality product.
The second model has been performed with a preliminary pressing process to 8mm. It was noted that needed load is less load needed in the first product. But some shortages appeared of the metal in the outlet of the die
toward outside area due to the presence allowances at the bottom of the die, which led to the loss of a part of the metal.
Figure (10) shows the relation between applied load and the punch pressing displacement during preliminary pressing to 19 mm and the final pressing for the second model. It is noted (second curved) that final pressing of metal forming path differs completely as compered with the first model. In second case there is inside die (load swing) where in the first model there is only compression inside the die, but in the second model 19mm height is suitable because of metal shortage appearance.
Figure (11) shows the relation between applied load and the punch pressing displacement during preliminary pressing to 17.1 mm and the final pressing for the second model. It's noted that load in the first stage and the final more
than in previous models as given in the table (1), and the product quality is better but with increase in metal at the base of the die due to clearance.
The fourth model of the work piece with the initial height (27 mm) done primarily pressing to higher (13.5 mm) by load of (28.5 KN) and the final pressing process carried out
by load of (115.8 KN) as given in figure (12). Figure (13) shows unfilled bottom of the die due to shortage of the metal in flange base, and thus the metal has not distributed and not fully filled the die internal space although the load is less than the other the models.
Figure 9. Relationship between applied load via the punch displacement without preliminary pressing
a b
Figure 10. Relationship between applied load via the punch displacement (a) at 19 mm height (b) final pressing stage
a b Figure 11. Relationship between applied load via the punch displacement (a) at 17.1 mm height (b) final pressing stage
a b
Figure 12. Relationship between applied load via the punch displacement (a) at 13.5 mm height (b) final pressing stage
Conclusions
It can be concluded that:
1. Process of flange pressing at one stage needs high stress regardless of the shape of the resulting model, to obtain good quality product with different heights.
2. Use of preliminary pressing in the first stage facilities the final process within the die with less stress and best flow of the metal within the die.
3. The best way of pressing process is that implemented with the second model. In which less disadvantages
product obtained compared with order methods in spite of higher load used.
References
1. Principles of production processes, D.Qahtan Khalaf al-Jubouri, the University of Baghdad, 1987.
2. Fundamentals of Modern Manufacturing, Groover, Mikell P., John Wiley & Sons, New York, 2000.
3. Manufacturing Processes by B.H Amsted, John Wiley & Sons, Inc, 1979
ПЕРВЫЕ ПОСЛЕВОЕННЫЕ РЕКОНСТРУКЦИИ КРЕКИНГ-УСТАНОВОК
Абубакарова Зарета Шааевна
кандидат техн.наук, доцент, Чеченский государственный педагогический институт, г. Грозный THE FIRST POSTWAR RECONSTRUCTION CRACKERS
Abubakarovo Zareta, Candidate of Science, assistant professor of Chechen State Pedagogic Instituite, Grozny АННОТАЦИЯ
В статье представлены послевоенные реконструкции крекинг-установок в России. Дана характеристика наиболее важных опытно-промышленных крекинг-установок. ABSTRACT
Ключевые слова: крекинг; бензин; крекинг-завод; термический крекинг; реконструкция; соляровая фракция. Key words: cracking; gasoline; cracking plant; thermal cracking; reconstruction; solar fraction.
Первые послевоенные реконструкции четырех установок однопечного солярового крекинга системы Винклер-Коха в три установки двухпечного крекинга мазута с легким крекингом мазута в первой печи и глубоким крекингом флегмы во второй печи были проведены в Баку в 1947г. В качестве сырья применялась смесь из 90% мазута и 10% соляровой фракции прямой гонки.
Проведение реконструкции дало возможность увеличить объем крекирования в 1,5 раза и сократить расход соляровой фракции с 40 до 11,6% от загрузки сырья, а также увеличить выработку автомобильного бензина на 15%. За проведенную реконструкцию начальник объединения «Азнефтезаводы» Р.Г.Исмаилов, гл. инженер В.С.Алиев и директор бакинского завода им. Сталина П.К.Пучков, были удостоены Государственной премии СССР.
В 1952г. в связи с возросшей потребностью в соляровых фракциях некоторые бакинские крекинг-установки системы Винклер-Коха были переведены на режим работы по схеме легкого крекинга (висбрекинга) мазута, раз-
работанной сотрудниками института нефти АН Азербайджанской ССР М.Ф. Нагиевым и И.С. Шевцовым совместно с заводскими специалистами. В качестве сырья вместо ранее используемой смеси из 90% мазута и 10% соляровых фракций применялся мазут без соляровых фракций.
В 1953-1955гг. на режим работы по схеме легкого крекинга были переведены ещё несколько крекинг-установок, которые по этой схеме работали недолгое время. В 1949-1955гг. в связи с появлением в Баку избытка масляного гудрона была предложена технология крекирования с двухступенчатым нагревом масляного гудрона. Этот способ позволил высвобождать ежегодно более миллиона тонн мазута прямой гонки, который использовался для получения светлых нефтепродуктов. Производительность установки при работе по этой схеме легкого крекинга гудрона составляла 1100-1250 т/сут, выход бензина - 9-10%, выход керосина и газа - 3%.
В 1953-1954гг. инженерами Бакинского крекинг-завода Б.Г. Гусейновым, Р.Г. Измайловым и М.И.
