steel plate
Hot rolled steel sheet and cold rolled steel sheet are two common forms of steel that have different production processes, properties and uses.
By definition, steel ingots or billets are difficult to deform at room temperature and are not easily processed, and are generally heated to 1100~1250°C for rolling, a rolling process called hot rolling. The temperature of hot rolled plate rolling is high, so the deformation resistance is small, and large deformation can be achieved. Take the rolling of steel plate as an example, the general thickness of continuous casting billet is about 230mm, while after roughing and finishing, the final thickness of 1~20mm. at the same time, due to the small width-to-thickness ratio of the steel plate, the requirement of dimensional accuracy is relatively low, and it is not easy to plate shape problems to control the convexity of the main. For the organisation requirements, generally through the control of rolling and cooling to achieve that is to control the opening temperature of finishing rolling, final rolling temperature and curling temperature to control the microstructure and mechanical properties of the strip.
Mainly used in the production of steel structural parts, bridges, ships and vehicles.
Adding special elements (P, Cu, c, etc.), it has good corrosion resistance and atmospheric corrosion resistance, and is used for the production of containers, special vehicles, and also for building structures.
High-strength steel plate with good stamping performance and welding performance, used in the production of automotive FRAME, WHEEL, etc.
Carbon steel, alloy steel and tool steel for general mechanical structure, used in the production of various mechanical parts after heat treatment works.
Used for the production of all kinds of cold rolled products, including GR, GI, colour coated plates, etc.
With good processing performance and compressive strength, it is used for the production of high-pressure gas pressure vessels filled with LPG, acetylene gas and various gases with an internal volume of 500L or less.
With good processing performance and compressive strength, used for the production of high-pressure gas pressure vessels filled with LPG, acetylene gas and various gases with an internal volume of 500L or less.
Stainless steel has good corrosion resistance, mainly used in food industry, surgical equipment, aerospace, petroleum, chemical and other industries.
Cold rolled steel is a steel plate that is further rolled below the recrystallisation temperature at room temperature to a target thickness. Compared with hot rolled steel plate, cold rolled steel plate is more accurate in thickness and has a smooth, beautiful surface. Cold rolled plate is generally no heating process before rolling. However, due to the small thickness of the strip, it is easy to appear plate shape problems. Moreover, the cold rolled product is a finished product, therefore, in order to control the dimensional accuracy and surface quality of the strip, a lot of very cumbersome processes are used. The production line of cold rolling is long, with many equipments and complicated processes. With the improvement of the user’s requirements on the dimensional accuracy, plate shape and surface quality of strip steel, the control model of the cold rolling mill set and the means of plate shape control are relatively more than that of hot rolling. And the temperature of the rolls and strips is also one of the more important control indicators by definition, the ingot or steel bad at room temperature is difficult to deform, not easy to process, most of the steel is rolled by hot rolling method. But because the surface of the steel at high temperatures is easy to generate iron oxide, so that the hot rolled steel surface roughness, size fluctuations, so the requirements of a smooth surface, precise size, good mechanical properties of steel, hot rolled semi-finished products or finished products as raw materials and then cold rolled method of production.
Cold rolled sheet and strip has a wide range of uses, such as automotive manufacturing, electrical products, rolling stock, aviation, precision instrumentation, and food canning. Cold rolled thin steel sheet is the abbreviation of cold rolled sheet of ordinary carbon structural steel, also known as cold rolled plate, commonly known as cold plate, sometimes misspelled as cold rolled plate. Cold plate is made from hot rolled steel strip of ordinary carbon structural steel, which is further cold rolled to a thickness of less than 4mm. Due to rolling at room temperature, does not produce iron oxide, therefore, cold plate surface quality, high dimensional accuracy, coupled with annealing treatment, its mechanical properties and process properties are better than hot-rolled sheet, in many areas, especially in the field of home appliance manufacturing, has gradually used it to replace the hot-rolled sheet.
As the cold plate is a hot plate in the cold rolling process, and cold rolling at the same time will carry out some surface finishing so cold plate in the surface quality (such as surface roughness and so on) than the hot plate to come to a good, so if the product after the sequence of painting and other coating quality there are high requirements, the general choice of cold plate, the other hot plate is divided into pickled and un-pickled plate, pickled plate surface due to the pickling of the so into the normal metal colour, but not cold rolled! So the surface is still not cold plate high, not pickled plate usually have oxide layer on the surface with, black, or the existence of iron oxide layer, commonly known as fire baked like and if the storage environment is not good, usually with a little embroidery.
In general, the hot plate and cold plate in the project its mechanical properties are considered no difference, although the cold plate in the cold rolling process there is a certain degree of work hardening, (but do not rule out the case of strict requirements for mechanical properties, then you need to differentiate), cold plate is usually a little higher than the yield strength of the hot plate, the surface hardness is also higher, the county body how to look at the degree of annealing of the cold plate. But no matter how annealed cold plate strength is higher than the hot plate.
Because of the hot and cold plate performance is basically not too much difference, so the forming performance of the factors affecting the difference in surface quality depends on its surface quality, because the surface quality of the cold plate to come to the good, so usually speaking of the same material of steel plate, cold plate than the hot plate forming the appearance of the effect of some of the better.
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