Mechanical properties of carbon structural steel

This kind of steel mainly guarantees mechanical properties, so its grade reflects its mechanical properties, expressed by Q+ numbers, where "Q" is the Chinese pinyin prefix of the yield point "Qu" word, the number indicates the yield point value, such as Q275 indicates that the yield point is 275Mpa. If the letters A, B, C, D are marked after the grade, it means that the quality of steel is different, the amount of S and P is reduced in turn, and the quality of steel is increased in turn. If the letter "F" is marked after the grade, it is boiling steel, the mark "b" is semi-killed steel, and the one who does not mark "F" or "b" is killed steel. For example, Q235-A·F indicates grade A boiling steel with a yield point of 235Mpa, and Q235-C indicates Grade C killed steel or special killed steel with a yield point of 235Mpa.