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Location:Home>>News>>Q&A » What are the causes of white rust and dark spots?
Dark spots are further oxidation of white rust. The main causes of white rust are:
Poor passivation, passivation film thickness is not enough or uneven; No oil on the surface or residual water on the strip surface; The surface of the strip contains water when it is rolled up. Passivation not completely dried; Getting wet or rain-soaked during transportation or storage; The storage time of finished products is too long; Galvanized sheet and other acid and alkali and other corrosive media contact or stored together.
Zhishang Steel has always been a pioneer in custom steel and special supplies, and has been recognized for its efforts in enhancing work efficiency and product quality. In addition to ISO9001:2015 certification, we also adhere to strict quality policies and proprietary procedures. If you have any questions, please contact us to provide the best type of product solution for your pre-painted, coil coating metal process, we will closely support after-sales service to ensure that your subsequent problems can be solved in a timely manner, if you have any questions, please send email to info@zhishangsteel.com, we look forward to serving you.
Zhishang Steel, specializing in domestic steel products trade, warehousing, processing and other services. The team has four service teams: Shandong Zhishang Steel Co., LTD., Shandong Zhiyiheng Trading Co., LTD., Tai 'an Zhishang Economic and Trade Co., LTD., Shandong Zhishang Steel Structure Co., LTD. Mainly engaged in steel coil, coated, stee···