When stainless steel pipes are cold-drawn or cold-rolled, some defects will inevitably occur. These defects will affect the quality of the finished stainless steel pipe products. Therefore, preventive measures must be taken for the formation of these defects.
The quality defects of the cold-drawn stainless steel pipes mainly include uneven wall thickness, outer diameter, surface cracks, surface straightness, and scratches. The unequal wall thickness of the cold-drawn stainless steel pipe is affected by factors such as the wall thickness accuracy of the pipe blank, the method of extubation, the deviation of the drawn center line, the shape of the hole, the deformation process parameters, and the lubrication conditions.
During the formation process, pay attention to the degree of wear of the fitting and drafting. In addition, in order to reduce the formation of cracks on the surface of drawn stainless steel pipes, suitable stainless steel pipe blanks should be used to repair the surface defects of stainless steel pipe blanks. During the pickling of stainless steel pipe blanks, it is necessary not only to avoid pickling but also to avoid the formation of pits or hydrogen. Crisp, but also to avoid the lack of pickling, to prevent the oxide scale is not clean, when used, but also to ensure the quality of stainless steel pipe annealing, use a reasonable method of extubation, select the appropriate deformation process parameters and tool shape, but also improve the extraction center Line adjustments and inspections. Enhanced stainless steel pipe pickling quality and lubrication quality, to ensure that the hardness and uniformity of the tool and the surface finish will help reduce the formation of straight stainless steel pipe and scratches.
Cold rolled stainless steel pipe quality defects and prevention, the main quality defects of cold-rolled stainless steel pipe include stainless steel pipe wall thickness unevenness, outside diameter, surface cracks, wrinkles, and folds, etc., enhance the accuracy of stainless steel pipe wall thickness is to ensure cold Rolled stainless steel pipe wall thickness is an important condition. To ensure the accuracy of wall thickness and pickling quality of stainless steel pipe, lubrication quality and the surface finish of rolling pipe tools is an important guarantee to enhance the accuracy of cold-rolled stainless steel pipe wall thickness, stainless steel pipe blanks should be avoided pickling or pickling, stainless steel The surface of the pipe blank is formed with pockmarks or residual iron oxide skin. The processing measures the cooling of the rolling pipe tool and the inspection of the surface quality of the tool and replaces the mandrel bar and the rolling groove block that do not meet the requirements.
Therefore, the measures to reduce the rolling force are all beneficial to increase the accuracy of the outer diameter of the stainless steel pipe, including annealing the stainless steel pipe, reducing the amount of rolling deformation, enhancing the lubrication quality of the stainless steel pipe and the surface finish of the pipe tool, etc. Materials with high strength and hardness are used to produce rolling pipe tools, and cooling and inspection of rolling pipe tools are strengthened. If serious abrasion of the rolling pipe tools is found, it must be replaced in time to avoid the occurrence of an ultra bad condition of the outer diameter of the stainless steel pipe.
Source: China Stainless Steel Pipe Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)