БРАТЬЯ И СЁСТРЫ
ответить на во Вот текст: Drawing consists of pulling metal through a die. One type is wire drawing. The diameter reduction that can be achieved in one die is limited, but several dies in series can be used to get the desired reduction. Sheet metal forming Sheet metal forming is widely used when parts of certain shape and size are needed. It includes forging, bending and shearing. One characteristic of sheet metal forming is that the thickness of the sheet changes little in processing. The metal is stretched just beyond its yield point (2 to 4 percent strain) in order to retain the new shape. Bending can be done by pressing between two dies. Shearing is a cutting operation similar to that used for cloth. Each of these processes may be used alone, but often all three are used on one part. For example, to make the roof of an automobile from a flat sheet, the edges are gripped and the piece pulled in tension over a lower die. Next an upper die is pressed over the top, finishing the forming operation, and finally the edges are sheared off to give the final dimensions. Forging Forging is the shaping of a piece of metal by pushing with open or closed dies. It is usually done hot in order to reduce the required force and increase the metal's plasticity. Open-die forging is usually done by hammering a part between two flat faces. It is used to make parts that are too big to be formed in a closed die or in cases where only a few parts are to be made. The earliest forging machines lifted a large hammer that was then dropped on the workpiece, but now air or steam hammers are used, since they allow greater control over the force and the rate of forming. The part is shaped by moving or turning it between blows. Closed-die forging is the shaping of hot metal within the walls of two dies that come together to enclose the workpiece on all sides. The process starts with a rod or bar cut to the length needed to fill the die. Since large, complex shapes and large strains are involved, several dies may be used to go from the initial bar to the final shape. With closed dies, parts can be made to close tolerances so that little finish machining is required. Two closed-die forging operations are given special names. They are upsetting and coining. Coining takes its name from the final stage of forming metal coins, where the desired imprint is formed on a metal disk that is pressed in a closed die. Coining involves small strains and is done cold. Upsetting involves a flow of the metal back upon itself. An example of this process is the pushing of a short length of a rod through a hole, clamping the rod, and then hitting the exposed length with a die to form the head of a nail or bolt.
Holidays at sea. I came to the Black Sea with my parents. We will be here for two weeks. I swim every day. The weather is always beautiful, the water is warm and clear. We swim and watch fish and jellyfish in the water. Sometimes we see starfish or sea shells there. Once we even saw a dolphin. We often sit on the beach and watch the ships go into the distance, or look at the many gulls gliding across the sea. We eat ice cream and fruit on the beach and lie in the sun. I have a good tan. I made a lot of friends and we play volleyball on the beach.
Отдых на море. Я приехал на Черное море с родителями. Мы будем здесь две недели. Я плаваю каждый день. Погода всегда прекрасная, вода теплая и прозрачная. Мы плаваем и наблюдаем за рыбой и медузой в воде. Иногда мы видим там морские звезды или морские раковины. Однажды мы даже увидели дельфина. Мы часто сидим на пляже и наблюдаем за тем, как корабли уходят вдаль, или смотрим на множество чаек, скользящих по морю. Мы едим мороженое и фрукты на пляже и лежим на солнце. У меня хороший загар. У меня появилось много друзей, и мы играем в волейбол на пляже.
I love my city. Everything is beautiful in it: from the delightful center, to the most remote edges. If I were asked what city I would like to live in, I would undoubtedly stay where I am. And, of course, there is one place that I particularly love.
My favorite place in the city is the Park. Every weekend, my family and I go there to ride the rides and get a charge of positive emotions. This is where I can see happy parents who are not busy with their work. And there I often buy sweets: popcorn and cotton candy. In the Park, in addition to entertainment, there are also beautiful landings, with magnificent trees of various types. In autumn, this green Kingdom turns into a fire Palace and it is very difficult to take your eyes off this picture. I also love this place because I often meet new people there. By the way, my best friend and I met there and now we often walk in the Park after school. We don't need money to do this. The Park has an area where you can have fun for free. There are a lot of different horizontal bars on this site, which we constantly climb. And then, tired but happy, we go home to return to the Park