Came out from the steel plate is coiled, these plates were flat after the machine Kaiping called "open flat." Higher stress level in open flat, so size is less stable. Kaiping operation with different process parameters, the internal stress distribution is also different, a vertical length of the different directions, the carrying capacity of the different. And the carrying capacity is difficult to measure with the general strength index. Thus, when open flat in the welding of the welding deformation will be very difficult to adjust. So the appearance of the parts requiring high quality can not be used to open flat. Open flat steel plate to be cheaper than the average. Flat open plate thickness 3-12mm, material is Q235 and Q345, the main origin in the military, economy first, Baotou, Puri and so on. The main purpose of container and non-pressure tank on. 
 Edit this paragraph the advantages of open flat: 
 One. Low cost and length of free decision; II. Convenient transportation, without regard to the size according to plate; III. Cutting convenient size according to actual needs cutting plate; IV. Can effectively save material. Such as a tank requires 6800 × 1500 × 6 of the plate 20, the market size is generally 6000,8000,9000 length steel plate, steel plate if the use of market, there will be more than small pieces of material generated. Use of open flat, you can directly use 6900 steel, saving material, which is the biggest advantage. In particular, stainless steel, saving material cost reduction effect is obvious. ; 
 Edit this paragraph to open flat Disadvantages: 
 Disadvantage is that there will be a great time in the welding of welding distortion, it is difficult to adjust. So the appearance of the parts requiring high quality can not be used in Kaiping