【Troubleshooting】Black dye has turned brown or faded. We will explain the causes and countermeasures.
Black dyeing treatment is a surface treatment that reacts iron products in a high-temperature alkaline solution to form a black oxide film known as magnetite (Fe3O4). It has rust prevention effects and benefits such as anti-reflection and aesthetic enhancement. Black dyeing of general steel materials (raw materials) usually results in a deep black finish. However, for some materials, such as cast iron or those that have been hardened, as well as alloy steels that contain high amounts of chromium or other nickel, the result may be a reddish-black or a light gray instead of black. Additionally, wire-cut surfaces may appear brownish, resembling rust. The following causes can be considered: - Residual oil (insufficient degreasing) - Inadequate removal of the oxide film - High content of components other than iron in the material, leading to uneven reactions - Rough surface of the material, resulting in uneven reactions The following countermeasures can be taken: - Strengthening degreasing and cleaning - Removal of the oxide film through acid washing - Removal of thick oxide films and uniformity of surface roughness through sandblasting - Selection of black dyeing solutions suitable for alloy steels (such as SUS) Based on years of experience, our company selects black dyeing processes tailored to the material and processing history. If you have any concerns about black dyeing, please feel free to consult us.
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Improvement of color unevenness in black dyeing, stabilization of appearance quality, enhancement of corrosion resistance.
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Sasagawa Plating Co., Ltd. (Sanjo City, Niigata Prefecture) is a company that performs metal surface treatments such as chrome plating, nickel plating, electroless nickel plating, and blackening. While we excel in mass production through automated lines, we also possess production equipment and know-how for manual processes, making us strong in handling a variety of small lots and short delivery times. ★ Customization Capability We adjust the type of plating and film thickness according to customer requests and propose optimal surface treatments. We can accommodate not only mass production but also prototypes or even a single piece. ★ Speedy Response We flexibly respond to urgent requests and achieve processing with short lead times (we have a record of as short as 2.5 hours). We are recognized for our expertise in mass production on automated lines, delivering high quality and short delivery times. ★ Diverse Plating Technologies Utilizing plating technologies cultivated over many years, we cater to products in various industrial fields. We have established collaboration with partner factories to meet diverse surface treatment needs. ★ Environmental Consideration We are equipped with our own wastewater treatment facility and strive to reduce environmental impact. In 2021, we introduced solar panels, achieving an annual savings of approximately 90,000 kWh.