How to deal with blackening of metal surface in Dalian

How to deal with blackening of metal surface in Dalian:

The temperature tolerance required for Dalian metal surface treatment is large. You can get a good surface between 135 ℃ and 155 ℃, but it takes some time. In actual operation, attention should be paid to the quality of rust removal and oil removal before blackening and passivation and oil immersion after blackening. The quality of blackening is often changed by these processes.

Analyze the contents of sodium nitrate, sodium nitrite and sodium hydroxide in the solution on schedule every week or so, so as to supplement relevant components in time. Generally, all solutions should be replaced after half a year of use. After the metal is "bluish", rinse it with hot soapy water for several minutes, and then rinse it with cold water. Then, rinse with hot water and blow in. The protective film obtained by this method is black, and its main component is composed of calcium phosphate and iron oxide. Its corrosion resistance and mechanical strength are higher than those obtained by alkaline oxidation method. The main components of black liquor are sodium hydroxide and sodium nitrite.

Dalian metal surface treatment the oxide film produced by this process has stable performance, can protect the ring chamfer and retaining edge from rust for a long time at room temperature, and the appearance quality of the bearing has been significantly improved.

In actual operation, attention should be paid to the quality of rust removal and oil removal before blackening and passivation and oil immersion after blackening. The quality of blackening is often changed by these processes. In addition to effectively and quickly removing rust, hydrochloric acid pickling is also easy to react with the steel substrate and release hydrogen, resulting in over corrosion of the substrate metal surface and hydrogen embrittlement, affecting the surface quality and strength of the workpiece. It is applicable to hydrochloric acid pickling and derusting of iron and steel parts. Specifically, it can be applied to pre-treatment and derusting of iron and steel hot-dip galvanizing, electroplating, electroless plating, surface phosphating, surface oxidation, automobile, household appliances, steel structure and other industries.

For Dalian metal surface treatment, add the calculated amount of water into the pickling tank (no water can be added when the concentration of industrial hydrochloric acid is less than 25%), then add the fog and corrosion inhibitor according to the concentration of 2% of the weight of hydrochloric acid, and fully stir evenly; No toxic and harmful gases are produced during use, and the effect of inhibiting hydrochloric acid mist is particularly good, so as to improve the working environment of the workshop; This product reduces the surface tension of the pickling solution, so as to accelerate the infiltration and permeability of the pickling solution on the steel surface, and accelerate the stripping and dissolution speed of the rust layer. Generally, the floating rust can be removed in about 5 minutes, and the rust removal speed can be adjusted according to the needs of users.