Metal steel in the complex marine environment is very vulnerable to corrosion from the impact of sea water, corrosion of marine microorganisms. In particular, once metal steel contacts with substances such as water vapor in seawater, the chemical reaction between them will break the protective layer and coating of metal surface, causing greater corrosion to metal steel structures. The marine corrosion environment is generally divided into five zones: tidal range zone, marine atmosphere zone, seawater immersion zone, spray splash zone and seabed mud zone. The corrosion types of metal steel structures mainly include atmospheric corrosion, galvanic corrosion, crevice corrosion and stress corrosion.
The boiler steel plate has certain machinability, good high-temperature structure stability, good physical and mechanical properties, good welding and cold bending properties, certain high temperature strength, oxidation resistance, etc. According to different working conditions, boiler steel plates can be divided into two categories: steel plates for manufacturing room and medium temperature pressure parts and steel plates for manufacturing high temperature pressure parts. From the perspective of material, boiler steel plate can be divided into two categories: special carbon steel plate and low alloy heat-resistant steel plate.
In 2022, the global economy was in turmoil. Influenced by the epidemic, global inflation continued to increase, the US Reserve raised interest rates, the devaluation of the RMB, the Russian-Uzbekistan conflict, and the outbreak of the energy crisis led to the rise of production costs and raw materia
When cutting thick plates of wear-resistant steel plates, with the increase of the thickness and hardness of the steel plate, the tendency of cracks at the cutting edge will become greater and greater. In order to prevent the occurrence of steel plate cutting cracks, the following methods can be followed when cutting. ① Preheating cutting: the most effective way to prevent steel plate cutting cracks is to preheat before cutting. The preheating temperature should reach about 100℃, and the maximum cutting speed depends on the steel plate grade and thickness. ② Low speed cutting: Another way to avoid cutting cracks is to reduce the cutting speed. If overall preheating is not possible, local preheating method can be used instead.
Wear resistant steel plate is a kind of good wear resistant special plate, which can well adapt to the working conditions requiring large area wear. The wear-resistant steel plate is composed of low-carbon steel plate and alloy wear-resistant layer. The thickness of alloy wear-resistant layer is generally 1/3~1/2 of the total thickness. The matrix is used to provide the strength, toughness, plasticity and other comprehensive properties required to resist external forces; The alloy wear layer provides the wear resistance required to meet the specified working conditions.
Low alloy structural steel refers to the steel with better properties than ordinary carbon steel by adding a small amount or trace alloying elements to ordinary carbon steel, which changes the properties of steel. When the amount of alloy added exceeds the general content of carbon steel in normal p
Carbon steel is a ferrocarbon alloy with a carbon content of 0.0218%~2.11%, and generally contains a small amount of silicon, manganese, sulfur and phosphorus. The hardenability is low and the tempering resistance is poor. The diameter of complete quenching in water quenching is generally only 15-18 mm; During oil quenching, the maximum diameter or thickness of complete quenching is only about 6mm, and it is easy to deform and crack. The thermal hardness is poor. When the working temperature of the tool is higher than 200 ℃, the hardness and wear resistance of the tool drop sharply.
Exercise is a kind of processing method that applies pressure on metal blank through forging machinery to make it produce plastic deformation so as to obtain certain mechanical properties, shapes and ruler pieces. The advantage of forging is that it can eliminate the as cast loose defects produced i
