Surface treatment is a process of changing the surface of metal materials

Surface treatment is a process of changing the surface of metal materials:

Dalian metal surface treatment is an ancient technology, and since there were humans on Earth, surface treatment has been a technology that humans have long mastered. The life of primitive humans was difficult and they lived in groups. In order to survive, they made stone tools and used grinding technology to make stone tools have sharp edges, producing a "sharp cutting" effect. In the Neolithic Age, the stone tools used by primitive people were ground throughout, with a delicate and smooth surface.

Metal heat treatment is a process of heating metal workpieces in a certain medium to a suitable temperature, holding them at this temperature for a certain period of time, and then cooling them in different media at different speeds. Its performance is controlled by changing the microstructure of the surface or interior of the metal material. The content of surface protection: electroplating, coating, chemical treatment layer; Electroplating includes (zinc plating, copper, chromium, lead, silver, nickel, tin, cadmium, etc.); Painting includes (paint coating, electrostatic powder spraying, and plastic spraying process); Chemical treatment includes (blackening treatment, phosphating treatment).

The main method is to use acidic or alkaline solutions to chemically react with oxides and oil stains on the surface of the workpiece, dissolve them in acidic or alkaline solutions, in order to remove rust, scale, and oil stains on the surface of the workpiece, By using nylon brush rollers or 304 # stainless steel wire (made of acid and alkali resistant solution steel wire brush rollers) to clean up, the goal can be achieved. In order to remove various foreign objects attached to the surface of the object (such as oil stains, rust, dust, old paint films, etc.), a good substrate suitable for painting requirements is provided to ensure that the coating film has good anti-corrosion performance, decorative performance, and certain special functions, Before painting, the surface of the object must be pre treated.

People refer to the work done for this type of treatment as pre coating (surface) treatment or (surface) pre-treatment. Metal surface passivation and rust prevention treatment are becoming increasingly important, as rust prevention treatment can greatly increase the corrosion resistance of products and prolong their service life. Even stainless steel products now require stainless steel environmental passivation treatment, otherwise it is difficult to achieve the required anti-corrosion effect. For this reason, during pre-treatment, do not use strong alkalis and strong acids for degreasing and etching. Because strong alkali can dissolve the rich aluminum first, while strong acid can dissolve the rich zinc phase first, forming pinholes and micro pores on the surface of die castings, and leaving behind strong alkali and strong acid solution, it is easy to cause peeling and bubble formation after plating.

Multi layer chromium plating is a cathodic protection coating of zinc alloy, so the coating must have a certain thickness to ensure that there are no pores in the coating. Otherwise, due to the negative electrode potential of zinc alloy, white powdery corrosion products of alkaline zinc carbonate are easily produced in humid air. Therefore, it is necessary to choose an appropriate coating thickness based on the product's usage conditions.