If the surface oxide scale of the 2205 stainless steel plate is not uniform, the surface finish of the base metal under the thick and thin places is also different. Therefore, when heat-treated by heat treatment, it is necessary to uniformly form scale. To meet this requirement, you must be aware of the following issues:
(1) If the 2205 stainless steel plate is attached with oil on the surface of the workpiece during heating, the thickness of the scale at the oil adhering portion and the thickness and composition of the oxide scale in other portions are different, and carburization occurs. The portion of the subcutaneous matrix metal that is carburized will be severely attacked by acid. When the heavy oil burner is initially burned, the oil droplets sprayed on the workpiece have a great influence.
(2) 2205 stainless steel plate If there are impurities on the surface, especially when organic matter or ash adheres to the workpiece, heating will of course have an effect on the scale.
(3) Differences in the atmosphere of the 2205 stainless steel plate furnace The atmosphere in the furnace varies from place to place, and the formation of the scale also changes, which is also the cause of unevenness after pickling.
In addition, if bricks, asbestos, etc., which constitute the gantry for heating the workpiece, contain water, the water will evaporate when heated, and the atmosphere directly contacting the water vapor will be different from the atmosphere of other parts, and the formation of scale will of course be It is different. Therefore, objects that are in direct contact with the heated workpiece must be thoroughly dried before use.
(4) 2205 stainless steel plate If the part of the treated part has residual scale before heat treatment, there is a part of the scale remaining and the part without the scale after heating, the thickness and composition difference of the scale may occur, causing pickling The back surface is not uniform, so not only the final heat treatment, but also the intermediate heat treatment and pickling should be paid attention to.
(5) There is a difference in the scale produced by the stainless steel surface in direct contact with the gas or the flame of the oil and the place where it is not in contact. Therefore, it is necessary to make the treatment member not directly contact the flame port when heating.
If the surface finish of the 2205 stainless steel plate is different, even if it is heated, the scale of the surface is not the same as that of the fine part. For example, in a place where a partial defect is cleaned and a place where it is not cleaned, the condition of forming a scale is different, so that the surface of the workpiece after pickling is uneven.