The yield rate is a comprehensive technical and economic index in the production of medium and heavy plates such as A514 grade E QT steel plate. Increasing the yield rate can not only reduce the loss of metal, but it is also vital to the economic benefits of the steel enterprise. The influencing factors of the yield of medium and heavy plates are various, for example, the variety structure, negative deviation rolling level, plate shape control level, cutting loss, rolling waste and burning loss, etc.
Chemical composition of A514 grade E QT steel plate, Q345D steel plate: C: ≤0.18; Si: ≤0.50; Mn: ≤1.70; P: ≤0.030; S: ≤0.025; Nb: ≤0.07; V: ≤0.15; Ti: ≤0.20; Cr: ≤0.30; Ni: ≤0.50; Cu: ≤0.30; N: ≤0.012; Mo: ≤0.10; Als: ≥0.015. Yield strength (MPa) of Q345D steel plate: ≤16mm: ≥345; 16-40mm: ≥335; 40-63mm: ≥325; 63-80mm: ≥315; 80-100mm: ≥305; 100-150mm: ≥285; 150-200mm: ≥275; 200-250: ≥275; 250-400: ≥265. Tensile strength of Q345D low alloy steel: 450-630(MPa). Elongation: ≥21. Impact test: -20 ℃: ≥34.
In March, the daily output of key iron and steel enterprises fell on a month on month basis, while the overall inventory of A514 grade E QT steel plate and so on steel materials was lower but still at a high level. In terms of production, in March, according to the key statistics, the cumulative average daily output of pig iron, crude steel and steel for iron and steel enterprises was 1.824 million tons, 1.695 million tons and 1.766 million tons respectively, down 2.1%, 3.1% and 1.7% on a month on month basis.
