Investigation of Different Types of Black Oxide-Forming Materials on Appearance Quality

In black oxide generation methods, selecting an alkaline compound capable of generating magnetite under suitable temperature conditions not only improves the protective quality of the resulting oxide but also prevents the loss of energy and raw materials. in this paper, the effects of various commonly used compounds, along with some additional additives, on specific methods were investigated. the optimal conditions for black oxide formation were identified as the appropriate composition ratio, a fixed temperature of 150°c, and a duration of 5 to 8 minutes, depending on the type of parts. in this study, ferrous sulfate was used to recover and improve the properties of the depleted solution, thereby reducing the consumption of solution and alkaline materials. the composition and temperature conditions identified in this study can be applied to carbon steel parts with different levels of carbon contents, including low, medium, and high carbon steel, which are commonly used in industry.