304 stainless steel surface quality is good or bad, mainly depends on the pickling process after heat treatment, if the heat treatment process before the formation of the surface thickness of the skin thickness, or tissue is not uniform, then pickling and can not improve the surface finish and uniformity. It is necessary to give full attention to heat treatment or heat treatment before the surface cleaning.
If the thickness of the surface of the stainless steel sheet is not uniform, the surface roughness of the base metal surface is different in the thick portion and the thin portion, and the surface oxide dissolves in the pickling and the erosion of the base metal in the scale attachment site , So that the surface of the steel sheet is uneven. Therefore, in the heat treatment, it is necessary to uniformly form the scale. To meet this requirement, the following issues must be noted:
Heat treatment pickling surface 304 stainless steel plate if the surface of the workpiece adheres to the oil during heating, the thickness and composition of the scale and other parts of the scale are different, and carburization occurs. The portion of the subcutaneous base metal that is carburized will be severely attacked by the acid. Heavy oil burner when the initial combustion of the oil droplets, if attached to the workpiece, the impact is also great. The fingerprint of the operator will also be affected when attached to the workpiece. Therefore, the bath as a member of the staff do not directly touch the stainless steel parts, do not make the workpiece stained with new oil. Clean gloves must be worn.
Heat treatment pickling surface 304 stainless steel plate
304 stainless steel surface of the workpiece if the cold attached to the lubricating oil, etc., must be in the trichlorethylene degreasing agent, caustic soda solution and then fully degreased with warm water washing, and then heat treatment.
Stainless steel plate If the surface of debris, especially the organic matter or ash attached to the workpiece, the heating will of course have an impact on the oxide.
Differences in the atmosphere of the stainless steel furnace The atmosphere in the furnace is different in different parts, the formation of oxide will change, which is caused by uneven acid pickling reasons. Therefore, in the heating, the furnace parts of the atmosphere must be the same. For this reason, the circulation of the atmosphere must also be considered.
In addition, if moisture is contained in the bricks or asbestos used for heating the workpieces, the moisture is evaporated upon heating, and the portions directly contacting with the water vapor are different from those of the other portions, and the formation of scale is of course Is different. Therefore, the object in direct contact with the heated workpiece must be adequately dried before use. However, after drying, such as at room temperature, in the case of high humidity, moisture will continue to condense on the workpiece surface. Therefore, it is best to dry before use.
304 stainless steel plate if the treatment of local residual heat treatment before the oxide scale, after heating the remaining parts of the oxide scale and no oxide of the site, there will be the scale of the thickness and composition of the differences caused by pickling the surface is not Uniform, so not only pay attention to the final heat treatment, but also pay full attention to intermediate heat treatment and pickling.
Gas break or the flame of oil directly contact the surface of stainless steel and did not come into contact with the place of the oxide are different. Therefore, it is necessary to keep the treating member from directly contacting the flame port during heating