Basic technology in the production of stainless steel pickling passivation treatment

1. Acid cleaning and passivation of stainless steel workpiece after the machining on the surface after machining usually remain at the end of the iron and steel and cooling emulsion such as dirt, can cause a blotch with stainless steel surface rust, so should be skimmed oil removal, reoccupy nitric acid cleaning, are removed at the end of the iron steel, and has carried on the passivation. 2. Before and after welding cleaning and pickling passivation because oil is a source of hydrogen, in the absence of clear grease will form the air pressure in the weld, and the low melting point metal pollution, Such as zinc rich paint) After welding will cause cracking, so before the stainless steel welding wire in the groove and 20 mm on both sides of the surface is clean, oil available acetone is swabbed, paint rust should be removed with emery cloth or stainless steel wire brush, reoccupy acetone rub-up. Stainless steel equipment manufacturing no matter adopt what kind of welding technology, welding after all to clean, all welding slag, spatter, stain and oxidation were put away, such as color removal methods including mechanical cleaning and chemical cleaning. Mechanical cleaning such as grinding, polishing and blasting shot peening, should avoid to use carbon steel brush, to prevent surface rust. To achieve the best corrosion resistance, it can be soaked in the mixed liquid of HNO3 and HF, or use pickling passivation paste. In fact often 4 californium 1 machinery cleaning and combined application of chemical cleaning. 3. Malleable cast parts cleaning after hot working such as malleable cast stainless steel workpiece, the surface often has a layer of oxide skin, lubricant, or oxide pollution pollutants including graphite, molybdenum disulfide and carbon dioxide. Should be dealt with through shot blast, salt bath and multichannel pickling process. Such as the stainless steel turbine blades process is: the salt bath ( 10分钟) - water quench ( 2. 5分钟) - sulfuric acid wash ( 2min) - cold water wash, 2min) -> alkaline potassium permanganate bath ( 10分钟) - cold water wash, 2min) - sulfuric acid wash ( 1雨) - cold water wash, 1分钟) -> nitric acid wash ( 1. 5分钟) - cold water wash, 1分钟) - hot water washing ( 1分钟) To air dry.