Q235與Q345的區(qū)別
不同:q235的屈服強度下限為235mpa,q345的屈服強度下限為345mpa(q的意義為漢字的"屈"字,后面的數(shù)值代表屈服強度下限)二者合金含量不同:q235為普通碳鋼,q345為低合金鋼。(與舊標準1591-88牌號對照12mnv、16mn 16mnre、18nb、14mnnb)
二.化學成份
牌號 | C | Si | Mn | P | S | V | Nb | Al | Ti |
Q345A | 0.20 | ≤0.55 | ≤1.70 | ≤0.045 | ≤0.045 | 0.02-0.15 | 0.015-0.060 | - | 0.02-0.20 |
Q345B | ≤0.20 | ≤0.55 | ≤1.70 | ≤0.040 | 0.040 | 0.02-0.15 | 0.015-0.060 | - | 0.02-0.20 |
Q345C | ≤0.20 | ≤0.55 | ≤1.70 | ≤0.035 | ≤0.035 | 0.02-0.15 | 0.015-0.060 | ≥0.015 | 0.02-0.20 |
Q345D | 0.18 | ≤0.55 | ≤1.80 | ≤0.030 | ≤0.030 | 0.02-0.15 | 0.015-0.060 | ≥0.015 | 0.02-0.20 |
Q345E | ≤0.18 | ≤0.55 | ≤1.80 | ≤0.025 | ≤0.025 | 0.02-0.15 | 0.015-0.060 | ≥0.015 | 0.02-0.20 |