There are two commonly used methods for surface treatment of blackening in Dalian: traditional alkaline heating blackening and later room temperature blackening. But the room temperature blackening process is not very effective for low-carbon steel. Alkaline blackening is subdivided, and there is a difference between once blackening and twice blackening. The main components of black liquor are sodium hydroxide and sodium nitrite. The temperature difference required for blackening is not significant, and a good surface can be obtained between 135 and 155 ℃, but the required time is only a bit short.

By blackening the metal surface, a dense oxide film is formed on the surface of the metal product, which can effectively improve the rust resistance of the product. When using metal products, they are not easily damaged due to rust. In this regard, the application of metal blackening technology can bring the benefits of extending the lifespan of metal products.

What is Dalian Blackening Surface Treatment

1. Blackening treatment is a blackening process. Blackening is a common method of chemical surface treatment, which involves producing an oxide film on the metal surface to isolate air and achieve rust prevention. When the appearance requirements are not high, blackening treatment can be used, and the surface of steel parts is blackened, also known as bluing.

2. The commonly used methods for blackening treatment include traditional alkaline heating blackening and later room temperature blackening, but the room temperature blackening process is not very effective for low-carbon steel. Alkaline blackening can be further divided into two types: once blackening and twice blackening. The main components of the blackening solution are sodium hydroxide and sodium nitrite. The temperature required for blackening is relatively high, and a good surface can be obtained at temperatures between 135 and 155 ℃.

During the use of the prepared working fluid, it may occasionally be immersed in hot workpieces. Local blackening agents may be carried out of the black groove, and film-forming substances may also continuously deposit on the surface of the workpieces. As the solution is consumed, the composition in the liquid gradually changes. The concentration of the solution should be regularly tested and analyzed, and new blackening agents should be added regularly based on the production volume to maintain the working fluid within a certain concentration range.

The oxide film generated by this process has stable performance and can protect the chamfer and edge of the ring from rust for a long time at room temperature. The appearance quality of the bearing has been significantly improved. In practical operation, it is important to pay attention to the quality of rust and oil removal before blackening the workpiece, as well as the passivation and oil immersion after blackening. The quality of blackening often varies due to these processes.