Stainless steel seamless tube surface inspection: stainless steel seamless tube inspection quality of black and white, mainly determined by the pickling passivation process after heat treatment, if the previous heat treatment process produced by the overview of air oxide thin, or institutional uneven values, then the use of pickling passivation is not as good as improving the smoothness and evenness of the overview. Therefore To richly recognize the heat treatment of heating or heat treatment before the overview removal. If the overview oxide skin of stainless steel seamless tube is thin and thick uneven value, the smoothness of the base metal material under the thick residence and thin residence overview is also contradictory, and the dissolution of the overview oxide skin during pickling passivation is contradictory to the corrosion level of the base metal material by the acid at the location of the oxide skin adhesion, therefore , the seamless tube overview is also uneven value. Therefore, in the heat treatment heating, it is essential to make it even value to produce oxide skin. To achieve this provision, it is essential to pay attention to the following difficulties: stainless steel seamless tube if the product workpiece overview adheres to oil during heating, the thin thickness of the oxide skin in the location of oil adhesion and other units of the thin thickness and composition of the oxide skin will contradict, and will produce nitrogen seepage. Air oxidation skin under the organization of the base metal material is nitriding the unit will be more serious to suffer from acid corrosion. Fuel oil natural gas burner to start ignition when the liquid droplets need to be sprayed out, if adhered to the product workpiece, the impact is also great. The fingerprint identification of the operator will also be affected when it adheres to the product workpiece. Therefore, the bath operator does not have to touch the stainless steel plate immediately with his hands, and does not have to make the product workpiece stained with new oil. Must wear clean rubber gloves for actual operation.
Stainless steel seamless pipe product workpiece overview if there is cold drawing adhering grease, etc., essential in trichloroethylene degreasing agent, anhydrous aluminum chloride aqueous solution rich degreasing and then clean up with warm boiling water, and then carry out heat treatment.
stainless steel pipe if the overview has dirty, put the code is organic compounds or ash adhesion products workpiece at the time, heating will naturally have an impact on the oxide skin.
stainless steel tube furnace atmosphere difference furnace atmosphere in the parts of the contradiction, the generation of oxide skin a will also appear to change, which is also the cause of the uneven value after pickling passivation. Therefore , when heating up, the atmosphere in each position in the furnace is essential not different. Therefore, it is also essential to consider the circulation of the atmosphere. There is also, constitute the heating product workpiece commonly used assembly platform brick, stone mian, etc., if with water, in the heating, water will need to volatilize, direct contact with water vapor unit and other units of the atmosphere will produce a difference, oxide skin generation naturally contradictory. Therefore, the objects in direct contact with the heated product workpiece are essential to be used only through rich air-drying. However, after air-drying, if it is placed at room temperature, the water will still condense on the overview of the product workpiece in the natural environment with high humidity. Therefore, it is good to air dry before use.
Stainless steel seamless tube if the part of the treatment piece has residual oxidation skin before heat treatment, after heating up the position with oxidation skin residue and the position without oxidation skin, it will show the difference in the thickness and composition of the oxidation skin, resulting in uneven value after pickling and passivation overview, so not only should we pay attention to the post heat treatment, but also pay rich attention to the management center heat treatment and pickling and passivation. There is a difference between the stainless steel plate outlined by the direct contact of the fire of air rest or oil and the oxide skin produced by the residence that did not touch. Therefore , it is essential to make the treatment parts not directly touch the fire mouth when heating up.
