牌號表示方法:鋼的牌號由代表屈服點的漢語拼音字母(Q)、屈服點數值、質量等級符號(A、B、C、D)三個部分按順序排列。
例如:Q390A
其中:Q——鋼材屈服的“屈”字漢語拼音的首位字母;
390­——屈服點數值,單位Mpa;
鋼的牌號和化學成分應符合下表規定。合金元素含量應符合GB/T13304對低合金鋼的規定。
低合金高強度結構鋼的牌號和化學成分
牌號 | 等級 | 化學成分(質量分數)(%) | ||||||||||
C≤ | Mn | Si≤ | P≤ | S≤ | V | Nb | Ti | Al≥ | Cr≤ | Ni≤ | ||
Q295 | A | 0.16 | 0.8~1.50 | 0.55 | 0.045 | 0.045 | 0.02~0.15 | 0.015~0.060 | 0.02~0.20 | |||
B | 0.04 | 0.040 | ||||||||||
Q345 | A | 0.20 | 1~1.60 | 0.55 | 0.045 | 0.045 | 0.02~0.15 | 0.015~0.060 | 0.02~0.20 | |||
B | 0.040 | 0.040 | ||||||||||
C | 0.035 | 0.035 | 0.015 | |||||||||
D | 0.18 | 0.03 | 0.03 | 0.015 | ||||||||
E | 0.025 | 0.025 | 0.015 | |||||||||
Q390 | A | 0.2 | 1~1.60 | 0.55 | 0.045 | 0.045 | 0.02~0.20 | 0.015~0.060 | 0.02~0.20 | 0.30 | 0.70 | |
B | 0.040 | 0.040 | 0.30 | 0.70 | ||||||||
C | 0.035 | 0.035 | 0.015 | 0.30 | 0.70 | |||||||
D | 0.030 | 0.030 | 0.015 | 0.30 | 0.70 | |||||||
E | 0.025 | 0.025 | 0.015 | 0.30 | 0.70 | |||||||
Q420 | A | 0.20 | 1~1.7 | 0.55 | 0.045 | 0.045 | 0.02~0.20 | 0.015~0.060 | 0.02~0.20 | 0.40 | 0.70 | |
B | 0.04 | 0.04 | 0.40 | 0.70 | ||||||||
C | 0.035 | 0.035 | 0.015 | 0.40 | 0.70 | |||||||
D | 0.030 | 0.030 | 0.015 | 0.40 | 0.70 | |||||||
E | 0.025 | 0.025 | 0.015 | 0.40 | 0.70 | |||||||
Q460 | C | 0.20 | 1~1.7 | 0.55 | 0.035 | 0.035 | 0.02~0.20 | 0.015~0.060 | 0.02~0.20 | 0.015 | 0.70 | 0.70 |
D | 0.030 | 0.030 | 0.015 | 0.70 | 0.70 | |||||||
E | 0.025 | 0.025 | 0.015 | 0.70 | 0.70 |