Anticorrosion has become an important problem in the construction of steel structure workshop

The steel structure workshop anticorrosion accident endangers the safe operation of steel structure and causes serious social and economic losses. This paper introduces and compares the common anticorrosion measures and surface treatment methods of steel structure for reference.

Steel structure workshop anti-corrosion measures:

(1) Weather-resistant steel: Weather-resistant steel is a kind of steel containing P, Cu, Cr, Ni, Mo and other alloying elements. Under certain temperature conditions, the ability of atmospheric corrosion resistance can be improved by forming a self-protective oxidation film on the base metal.

Hot dip zinc: hot dip zinc is in about 600℃ high temperature molten zinc leaching rust removal steel, so that the steel surface adhesion zinc layer, so as to achieve the purpose of corrosion prevention. The process has good corrosion resistance, long production life, high degree of industrialization and stable product quality, so it is widely used in outdoor steel structure engineering which is seriously corroded by atmosphere and difficult to repair, such as power transmission tower and communication tower. At present, hot dip zinc is also used to prevent corrosion of profiled steel plate in light steel structure system.

Thermal sprayed aluminum (zinc) coating: Thermal sprayed aluminum (zinc) coating is also a long-term corrosion protection treatment. The practice shows that the surface of steel parts is treated with sand blasting to make the surface appear metallic luster and hair. On the surface of the steel parts for a thermal spraying equipment heat source (acetylene - oxy combustion, arc, plasma arc, etc.), the continuous aluminum (zinc) wire melting, and compressed air blowing on the surface of the steel parts, forming a honeycomb aluminum (zinc) spraying layer (thickness of about 80μm~100μm); A composite coating is formed by filling the pores with a coating, such as epoxy resin or neoprene paint. This method cannot be applied to the inner wall of smaller tubular members, so both ends of tubular members must be airtight to prevent corrosion of the inner wall.

Coating method: coating method anticorrosion ability is generally not as good as long-acting method, its one-time cost is low, but the maintenance cost is relatively high. The first step of coating construction is rust removal, high quality coating must be thoroughly rust removal. The choice of coating should consider its environmental factors, different coatings have different corrosion resistance to different corrosion conditions.

Coating has primer, lacquer and finish paint commonly 3 kinds. The primer contains more powder, less base material, rough film forming, and strong stickiness with steel; The role of intermediate paint is to increase the thickness of the coating, improve the shielding performance of the whole coating system, for primer and finish, intermediate paint to have good adhesion; The base material of the finish is much, the film is shiny, can protect the primer from atmospheric corrosion, and can resist weathering. Attention should be paid to the compatibility of different coatings.

Coating is widely used because of its convenient construction and good antiseptic effect. At present, coating protection measures are widely used to prevent corrosion of steel Bridges in China, and their recommended standards for railway and highway industries have been formed.

Steel structure coating testing.

(5) the cathodic protection, cathodic protection technology is a kind of electrochemical protection technology, its principle is based on the metal oxide anode, protected structures into cathode, anode loss of metal ions, electrons and electron flow through cable to the cathode, enrichment of electronics at the cathode, the cathode won't produce electronic, won't lose metal ions, and thus prevent or reduce the occurrence of corrosion. In recent years, cathodic protection has been widely used to protect metal structures and in water.

Coating thickness can be nondestructive measurement of non-conductive coating thickness of non-magnetic metal substrate (such as steel, iron, alloy and hard magnetic steel)(such as aluminum, chromium, copper, enamel, rubber, coating, etc.) and non-magnetic metal substrate (such as copper, aluminum, zinc, tin, etc.)(such as enamel, coating, coating, plastic, etc.). Coating thickness tester with its measurement error is small, high reliability, good stability, simple operation and other characteristics, become an indispensable testing instrument to control and ensure product quality, widely used in manufacturing, metal processing, chemical industry, commodity inspection and other industries.