Hot-rolled steel is a steel that has been heated and rolled at a high temperature. Its strength is not very high, but it is sufficient for our use. Its plasticity and weld-ability are good, so we use it more often; cold-rolled steel is ordinary hot rolling. Steel is strongly drawn beyond the steel in the strain hardening stage, its strength is high, but the toughness and weld-ability are poor, relatively hard and brittle! Hot rolling is the heating of the material during the rolling process or before rolling. Rolling is generally carried out after heating to a temperature above the crystallization temperature. Such as: 1000 degrees or more, hot rolling is processed at high temperatures. Allow the interior of the steel to recrystallize. Let it be more excellent. However, hot rolling does not change the structural properties of the metal. Cold rolled steel is steel that has been produced by cold rolling. Cold rolling is a steel sheet in which the No. 1 steel sheet is further rolled to a target thickness at room temperature. Compared with hot-rolled steel sheets, cold-rolled steel sheets are more precise in thickness and have a smooth and beautiful surface, as well as various superior mechanical properties, especially in terms of processability. Because cold-rolled raw rolls are brittle and hard, they are not suitable for processing. Therefore, cold-rolled steel sheets usually need to be given to customers after annealing, pickling and surface smoothing. The maximum thickness of cold rolling is 0.1--8.0MM or less. For example, the thickness of cold-rolled steel sheets in most factories is 4.5mm or less; the minimum thickness and width are determined according to the equipment capacity and market demand of each factory. The difference between cold rolled steel and hot rolled steel is not in the smelting process, but in the rolling temperature, or the rolling end temperature. When the finish rolling temperature is lower than the crystallization temperature of the steel, it becomes cold rolled steel. Hot-rolled steel is easy to roll, and the rolling efficiency is high, but the steel is oxidized under hot rolling conditions, and the surface of the product is black and gray. Cold-rolled steel requires high rolling mill power, low rolling efficiency, and intermediate annealing in order to eliminate work hardening during rolling, so the cost is also high, but the cold-rolled steel surface is bright and of good quality and can be directly used for processing. Finished products, especially the cold rolled steel plate is widely used.

Stainless steel Seamless pipe production companies are aware that the so-called stainless steel seamless pipe and carbon steel seamless pipe differences, mainly refers to the difference between the stainless steel and carbon steel planning rules, that is to say, the two kinds of steel planning rules can not be universal. The differences are as follows: First, the cold processing of stainless steel processing hardening, for example, zigzag with anisotropy, that is: horizontal and vertical functions are different. Can use the strength increased by cold processing, but if compared with the total area of the tortuous area is small, ignoring this addition, the increase in strength can be to a certain extent improve the safety factor. Second, the stress/strain curve shape is different, the elastic limit of stainless steel is about 50% of the yield stress, the minimum value of the rule in the norm, the yield stress value is lower than the yield stress value of medium carbon steels. Three, stainless steel does not yield point, usually Ó 0.2来 show that the yield stress is considered equivalent value.

The cold-formed steel raw material is hot-rolled coil , and most of the coils used for cold-formed steel have no thickened plates at all. Therefore, in the case of no welding, most of the cold-formed steels are flat at various plane thickness scales, and hot rolling The inner wall of the GB channel flange is a bevel. The outer wall and the inner wall are parallel. The thickness of the engineering machinery is also changed. The most important thing is that the hot-rolled channel is almost thicker than the flange. In addition, the outer R angle of the cold-formed steel is larger than the inner R angle, and the outer R angle of the hot rolling is sharp and the inner R angle is large. Other hot-rolled sections are unlikely to be as thin as cold-rolled sheets, while cold-bending is based on sheet thickness. The cold-bent angle steel is at a fixed point orientation, the inner R angle is larger than the outer R angle, and the hot-rolled angle steel is opposite, and even the strict remote control of the scale can be said that the outer R angle is opposite to the inner R angle, and the thickness is the same as the channel steel. . Welded H-beams and hot-rolled H-beams are difficult to see in appearance, especially approximate specifications. However, the weld is still very obvious, and the hot-rolled H-beam is the R-angle of the oil-slip transition at the link between the web and the flange. I-beams are not welded for the simple reason that there are no hot rolled coils with bevels . If you have to do it, the cost is much higher than hot rolling. In addition, the I-beam under different gauge systems has different slopes, and the slope is not expressed in the specification.

Since the surface of the stainless steel tube will form a thin protective film, although the protective film is about 3×10-6 mm, it is very tough. Even if it is destroyed, as long as there is oxygen next to it, it can be regenerated immediately to prevent rust. As long as you know the characteristics of stainless steel and use it correctly. Under the condition of less corrosiveness such as water pipes or hot water of 100 °C, there is almost no need to worry about rusting, and there is no need to worry about the smaller inner diameter or the increase of resistance caused by the common "rusting projections" generated in galvanized steel pipes. Larger phenomenon, you can get water flow that will not be blocked. Thin-walled stainless steel pipes require only about one-third of the thickness of galvanized steel pipes due to their high corrosion resistance and mechanical properties. Therefore, the weight of the pipe is greatly reduced, and the cost is also reduced, making the handling easier and the installation more convenient.