The alloying elements of low alloy steel are less than 5%. The low alloy steel is added one or several alloy elements on the basis of carbon steel to improve the performance. Such as manganese, silicon, aluminum, nickel, copper, boron, phosphorus, rare earth, etc. A709 Gr 50W bridge steel plate Steel with one or more of these elements will have the advantages of high strength and toughness. Due to the addition of few alloy elements, it is called low alloy high strength steel.
The characteristic of niobium in A709 Gr 50W bridge steel plate etc. steel material is to increase the recrystallization temperature of austenite, so as to achieve the purpose of refining austenite grains. In general, the amount of niobium added in steel material is less than 0.05%, and the contribution of niobium above 0.05% to strengthening and toughening will no longer be obvious.
Medium and heavy plate is widely used in construction engineering, machinery manufacturing, container manufacturing, shipbuilding, bridge construction and other fields. The surface quality of medium and heavy plate mainly refers to its surface smoothness, surface defects, etc., which is one of the main quality indexes of medium and heavy plate. The surface quality of A709 Gr 50W bridge steel plate, medium and heavy plate not only affects the appearance of the products, but also reduces the corrosion resistance, wear resistance, fatigue limit and other properties of the steel plate.
Safety awareness is the basic understanding and thinking of safety in people's mind, which directly affects people's behavior and habits. In the report of the 19th National Congress of the Communist Party of China, General Secretary Xi clearly pointed out: Establish the concept of safe development and promote the idea of life first and safety first. Therefore, improving employees' safety awareness is an important way for steel companies to strengthen safety management. First, there must be a correct understanding. Ensuring personal safety is not only to ensure safe production, improve corporate efficiency, and promote corporate development, but also to be responsible to relatives, to the family, and most importantly to oneself.
