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Cold Rolled Stee And Hot Rolled Steel
May 31, 2017

Cold rolled stee is cold rolled stee production. Cold rolling is a steel sheet in which the No. 1 steel sheet is further rolled to a desired thickness at room temperature. Compared with hot-rolled steel, cold-rolled steel plate thickness is more accurate, and the surface is smooth, beautiful, but also has a variety of superior mechanical properties, especially the processing performance. Because the cold rolled original roll is more brittle, not suitable for processing, so usually cold rolled stee plate after annealing, pickling and surface after leveling to the customer. The maximum thickness of cold rolling is 0.1 - 8.0MM the following, such as most of the cold-rolled steel plate thickness is 4.5MM below; minimum thickness, width is based on the plant's equipment capacity and market demand and decide.

The difference between cold rolled and hot rolled steel is not in the smelting process, but in the rolling temperature, or the rolling temperature. The finish rolling temperature is lower than the recrystallization temperature of the steel to become cold rolled stee. Hot rolled steel is easy to roll, steel rolling efficiency is high, but hot rolling conditions, steel oxidation, the product surface is dark gray. Cold rolled stee requires high rolling mill power, rolling efficiency is low, and the rolling process in order to eliminate the work hardening also intermediate annealing, so the cost is higher, but the cold-rolled steel surface bright, good quality, can be directly used to process Finished, so cold rolled steel plate is widely used.

The hot rolled coil was used as raw material, and the iron oxide was removed by pickling and then subjected to cold rolling. The finished product was rolled hard rolled, and the hardness and hardness of the hard rolling were increased due to the cold hardening caused by continuous cold deformation. , So stamping performance will deteriorate, only for simple deformation of the parts. Rolling hard rolls can be used as raw materials for hot-dip galvanizing plants, since hot-dip galvanizing units are equipped with annealing lines. Rolling hard roll weight is generally 6 to 13.5 tons, coil at room temperature, hot rolling acid scrubbing continuous rolling. The inner diameter is 610mm.

Under normal circumstances, hot rolling than the cold rolling of the mechanical properties of the better, after heat treatment of steel, its tensile strength, yield strength, plasticity, toughness will be improved, in addition, I feel very important point, heat treatment can eliminate residual Stress, and cold rolling may be due to the process of steel yield yield of uneven deformation, will produce residual stress, the residual stress on the stability of a great impact. Hot rolling and cold rolling are all steel or steel plate forming process, they have a great impact on the organization and performance of steel, steel rolling mainly hot rolling mainly cold rolled only for the production of small steel and thin plate.

The advantage of hot rolling is that it can destroy the casting structure of the ingot, refine the grain of the steel, and eliminate the defects of the microstructure, so that the steel structure is dense, the mechanical properties are improved. This improvement is mainly reflected in the rolling direction, so that the steel to a certain extent is no longer an isotropic body; pouring the formation of bubbles, cracks and loose, but also in the high temperature and pressure under the welding.