If the surface of the stainless steel plate is not uniform, it is necessary to make a uniform oxide skin in the process of heat treatment. To achieve this goal, in addition to the high surface quality of stainless steel plates, it also depends on whether the pickling process is in place. Therefore, we must pay attention to the surface cleaning of stainless steel plates before heating and heat treatment before heat treatment. The following is to focus on the relationship between the surface quality of the stainless steel plate and the heat treatment process.
First of all, if the surface of stainless steel plate is attached to oil when heated, the thickness of oxide scale on the area of oil attachment is different from that of other parts, and it will also lead to carburizing. The parts of the oxidized subcutaneous stainless steel matrix that are carburized are seriously eroded by acid. The oil droplets that are sprayed at the beginning of the burning of the heavy oil burner will have a larger impact if they are attached to the stainless steel plate.
In addition, the operator’s fingerprints also have adverse effects on the stainless steel plate. Therefore, the operation can not directly touch the stainless steel plate, stainless steel plate, don’t let the dip in the new oil, such as oil plate cold processing if there is left, must be in the trichloroethylene degreasing agent, caustic soda solution and then use fully skimmed warm water to thoroughly clean, then do heat treatment processing.
If the surface of stainless steel plate has impurities, especially when organic matter or ash is attached to the surface of stainless steel plate, heat treatment will have a negative effect on the oxide scale.
In addition, the surface of the stainless steel directly exposed to the flame is also different from that produced in the area without contact. Therefore, when heated, it must not be allowed to contact the flame directly.
If the local processing of stainless steel in heat treatment before there is a residual oxide, oxide and residual parts and no oxide parts after heating, different thickness and composition can produce oxide on the surface resulting after pickling is not uniform, so should pay attention not only to the final heat treatment, but also completely note that the middle heat treatment and pickling.
The surface finish of stainless steel will also be affected. If the surface finish is different, even if the same heating is applied, the surface roughness area of the stainless steel plate is different from that of the fine area. For example, in the area where the partial defects are cleared and not cleaned, the oxide scale is also different, which will lead to the uneven surface of the stainless steel plates after pickling.
The last point is the difference of the atmosphere in the furnace. The different atmosphere in each part of the furnace will also lead to different changes in the oxide scale. This will also lead to uneven after acid washing. Therefore, in the heating, the atmosphere in the various regions of the furnace must be kept the same, and this must consider the circulation of the atmosphere.
Source: China Stainless Steel Plates Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)