Use different than cold-rolled and hot-rolled sheets?
the Most popular kind of metal is sheet metal, which is used almost in all spheres of mechanical engineering and other industries. Sheet metal surrounds us everywhere: from car in a coal mine to a covering of high-speed trains, from the buckle on your belt to the space Shuttle. If we talk about "black" the metal, it is necessary to distinguish between hot rolled and cold rolled sheets. A simple man does not see significant difference between them, but sometimes this difference is a fundamental one.
If you need to buy sheet steel, then you need to understand the differences of these 2 types of steel, not to spend the extra money and get exactly the material that fits you. Professionals know this information for a long time, but it is useful to refresh them in my memory. And for those who are faced with metal the first time or sporadically, most likely, this information will be new.
As you can see from the title, the difference between these types of metal lies in the method of their production, but this greatly affects their areas of use and har-Ki.
the Difference in production
To receive sheet metal "slabs" (blank) is passed successively through a pair of rollers, in consequence of which the thickness of the block gradually decreases and at the same time he stretches outwards and along. Rolling can be done on hot or cold metal.
Initially, it may seem that a cold car will be cheaper because there is no need to monitor the temperature, heating the workpiece and provide high resistance to fire. But it is not so. The cold rolled metal less plastic, therefore it is necessary to apply more powerful and durable machines. Also, after cold rolling to remove tension in the metal - its so and so need to burn, heat and compressing. That is why it will be cheaper for the same cold rolling sheet.
But in the hot rolling process also has problems. The steel has a mixed structure, therefore, the heat capacity, plasticity, strength and elasticity vary even within the 1st billet. You also need to understand that to ensure uniform heating of the entire workpiece is technically impossible. From this comes up, what better warm up the area of the workpiece to be rolled easier than a cooler. In the end appearance the variations in width and thickness that only increase after cooling of the steel sheet.
hot car involves air oxidation of the metal surface. Therefore, g/sheet is very easy to distinguish from the x-sheet by the presence of scale. The better quality cold-rolled sheet, and hot rolled is cheaper.
What comes up? G/to metal is less than smooth, he has variations of thickness and there is dross. Cold metal does not have these disadvantages, but it is much more expensive.
What then shall we choose? It all depends on the industry of its application. Because of durability and strength difference between these 2 types of metal is very slight, unless there are increased requirements to the surface of the sheet - you can do y to metal.
Translated by "Yandex.Translate": translate.yandex.ru.