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 S355ML VS S355J2, 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.
A514 gr K quenched and tempered alloy steel chemical composition (melting analysis)%C: 0.10-0.20, Si: 0.15-0.30, Mn: 1.10-1.50, P max.: 0.035, S max.: 0.035, Mo: 0.45-0.6.0, B: 0.001-0.005The mechanical properties in thickness (mm)T≤65Yield strength (≥Mpa): 690Tensile strength (Mpa):760-895Elongation in ≥, %: 18
Under the action of the roller and the plug, a cavity is formed in the blank, which is called the blank. Then send it to the automatic tube rolling machine to continue rolling. Finally, the wall thickness of the whole machine is equalized and the diameter is calibrated by the sizing machine to meet the specification requirements. It is an advanced method to produce S355ML VS S355J2, hot-rolled seamless steel tube by continuous rolling mill.
The S355ML VS S355J2 steel making furnace can only be used as primary refining, and the refining needs to be completed in the refining equipment outside the furnace, which is also called secondary refining. It is mainly through decarburization, desulfuration, denitrification and dephosphorization to improve the cleanness of the steel, to establish a chromium molybdenum low alloy steel with good oxidation resistance and high temperature strength, to remove unwanted harmful impurities from the steel, and to improve the S355ML VS S355J2 internal quality of the steel.