The wear-resistant layer of wear resistant steel NM400 wear-resistant steel plate is mainly composed of chromium alloy, and other alloy components such as manganese, molybdenum, niobium and nickel are added. The carbide in the microstructure is distributed in the form of fiber, and the direction of the fiber is perpendicular to the surface. The microhardness of carbides can reach hv1700-2000 and HRC58-62 respectively. The alloy wear resistant steel NM400 carbide has strong stability at high temperature, high hardness and good oxidation resistance. It can be used normally within 500 ℃.
The effect of nitrogen on steel performance is similar to that of carbon and phosphorus. With the increase of wear resistant steel NM400 nitrogen content, the strength of steel can be improved, plasticity especially toughness can be significantly reduced, weldability becomes worse, and cold brittleness is intensified. Nitrogen with aluminum, niobium, vanadium and other elements can reduce its adverse effects, improve the performance of wear resistant steel NM400 steel, can be used as an alloying element of low alloy steel.
In the whole steel structure and steel body, the medium and heavy plate is an important part, once the problem occurs, it is easy to fracture, collapse and occur explosion. So how to judge whether the medium and heavy plate, wear resistant steel NM400 is of high quality? First of all, check whether there are cracks on the surface of the wear resistant steel NM400 plate and how glossy it is. Secondly, to measure the thickness error of medium and heavy plate, it is better to use the instrument to measure the bending tensile value. Finally, observe the scale of the steel plate manufacturers, whether there are relevant qualification certificates, and how the production process is.
The main applications of normalizing are as follows:① For low carbon steel, wear resistant steel NM400. The hardness of low carbon steel after normalizing is slightly higher than that after annealing, and the toughness is also better, so normalizing can be used as the pretreatment of cutting.② For medium carbon steel, normalizing can be used as the final heat treatment instead of quenching and tempering treatment, or as the preparation treatment before surface quenching by induction heating.③ Normalizing can be used in tool steel, bearing steel, carburizing steel and so on, which can eliminate or inhibit the formation of network carbide, thus obtaining the good microstructure needed for spheroidizing annealing.④ Normalizing can refine the cast structure and improve the machinability of steel castings.