Q345E steel plate is a low-alloy high-strength steel plate with good low-temperature impact performance. The steel grade is composed of three parts: Q (Qufu in Chinese spelling) representing yield strength, yield strength value, and quality grade symbol. S420M material, Among them: Q represents the yield strength; 345 represents the yield strength value, unit MPa; E represents the grade (passed -40 degrees impact test).
A small amount of Nb is sufficient to obtain excellent comprehensive properties of S420M material etc. steel material, because at low Nb concentration, the yield strength of steel material increases faster and is proportional to the concentration, but when the Nb content is greater than 0.03%, the strengthening effect begins to decrease. Studies have shown that when the Nb content is greater than 0.06%, excess Nb will no longer strengthen the steel material.
What is the specific use of S420M material, hot rolled plate in daily life? First of all, hot rolled plate is used in bridge, vehicle structure, frame and other fields to play a role of bearing pressure. Secondly, high pressure boiler vessels are also made of hot rolled plates, which can be heat-resistant and airtight, and can stably seal the hot gas in the container. Thirdly, stainless steel hot rolled plate can be used to process hardware products. It has excellent corrosion resistance, and is easy for processing.