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304 Stainless Steel Pipe Surface Quality Inspection Method

Dec. 10, 2019

What is the quality inspection method and important points of 304 stainless steel pipe? The following 304 Stainless Steel Plate Suppliers will come to tell you one by one.


304 stainless steel pipe profile quality inspection: The quality of the 304 stainless steel pipe profile is black and white. The first decision is the pickling process after thermal treatment. If the profile of the oxide layer formed by the previous heat treatment process is thick or the structure is uneven, pickle and Can not improve the profile finish and averageness. So it is necessary to enrich the heat treatment or the general cleaning before heat treatment. If the thickness of the stainless steel pipe is uneven, the surface finish of the base metal under the thick and thin spaces is also different. When the surface is pickled, the ablation of the oxide scale and the level of erosion of the base metal by the oxide scale are affected by acid. Differences, so the steel pipe profile is uneven. Therefore, during heat treatment, it is necessary to uniformly form oxide scale. To meet this requirement, it is necessary to pay attention to the following problems: If the stainless steel steel pipe is attached with oil when the workpiece is heated, the thickness of the scale on the oil adhered to the thickness and composition of the scale of other departments will be different, and carburization will occur. The carburized parts of the substrate metal below the oxide scale will be severely attacked by acids. If the oil droplets ejected from the heavy oil burner during the initial combustion are attached to the workpiece, the influence will also be great. It is also affected when the fingerprint of the operator is attached to the workpiece. Therefore, the operator should not directly touch the stainless steel parts with his hands, and the workpiece should not be stained with new oil, and must be operated with clean gloves.


304 Stainless Steel Pipe Surface Quality Inspection Method


304 Seamless Stainless Steel Pipe


304 Seamless Stainless Steel Pipe is lubricating oil adhered during cold working, it must be degreased in trichloroethylene degreaser and caustic soda solution, then washed with warm water, and then heat treated. If the stainless steel pipe has debris in it, if it is organic or ash is attached to the workpiece, the heating will of course affect the scale. The difference in the atmosphere of the stainless steel tube furnace. The atmosphere in the furnace is different in each part, and the formation of oxide scale will also change. This is also the reason for the unevenness after pickling. Therefore, when heating, the atmosphere in each part of the furnace must be the same. In addition, if the bricks, asbestos, etc. that make up the stand used for heating the workpiece contain moisture, the moisture will evaporate when heated, and the atmosphere of the department directly in contact with water vapor will be different from that of other departments. Of course, the formation of oxide scale will also occur. Just disagree. Objects in direct contact with the heated workpiece must be fully dried before being used. However, if left at room temperature after drying, moisture will still condense on the workpiece profile in a high humidity environment. Therefore, it is best to dry before use. If the 304 stainless steel pipe has residual scale on the part of the treatment part before the thermal treatment, there will be differences in the thickness and composition of the scale after the heating and where there is no scale on the scale, which will cause the profile after pickling. Not even, so not only focus on final heat treatment, but also focus on central heat treatment and pickling. There is a difference between the profile of stainless steel that is directly contacted by gas or oil flame and the scale that occurs in non-contact spaces. Therefore, it is necessary to prevent the treatment member from directly contacting the flame mouth during heating.


The above is the 304 stainless steel pipe surface quality inspection method introduced by 304 Stainless Steel Coils Manufacturer. Hope to help everyone.

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