Product Name：DIN Neck Flat Welding Flange
With neck flange is a special term, divided into with neck flat welding flange and with neck butt welding flange. International standard for pipe flange can be summarized as two different and non-interchangeable pipe flange systems.
How is the logo printed on the stainless steel flange
Surface natural color whitening treatment: During the processing of stainless steel flanges, black oxide skin is produced after coiling, rimming, welding or artificial surface heat treatment. This hard gray-black oxide scale is mainly composed of NiCr2O4 and NiF, two EO4 components. In the past, hydrofluoric acid and nitric acid were generally used for strong corrosion removal.
⑴Chemical oxidation coloring method: It is the color of the film formed by chemical oxidation in a specific solution. There are dichromate method, mixed sodium salt method, sulfurization method, acid oxidation method and alkaline oxidation method. Generally "INCO" (INCO) is used more, but if you want to ensure the color of a batch of products are consistent, you must use a reference electrode to control.
⑵Electrochemical coloring method: the color of the film formed by electrochemical oxidation in a specific solution.
⑶ ion deposition oxide coloring chemical method: the stainless steel flange workpiece is placed in a vacuum coating machine for vacuum evaporation plating. For example: titanium-plated watch cases and watch bands are generally golden yellow. This method is suitable for mass product processing. Because of the large investment and high cost, small-volume stainless steel flange products are not economical.
