进步
Q235B 与 Q355B: 您应该指定哪种结构钢?
Q235B 与 Q355B: 您应该指定哪种结构钢?
In Chinese steel specifications, Q235B 和 Q355B are the two workhorse structural grades. The difference is not subtle — it affects section size, weight and cost. Getting the choice right at the design stage saves money later.
What the Numbers Mean
这 “问” stands for yield point (qufu), and the number is the minimum yield strength in MPa. Q235B yields at 235 兆帕; Q355B yields at 355 MPa — roughly 50 % stronger. 这 “乙” means a Charpy V-notch impact test at +20 ℃.
| 财产 | Q235B | Q355B |
|---|---|---|
| 屈服 (兆帕) | ≥ 235 | ≥ 355 |
| 拉伸 (兆帕) | 375 – 460 | 470 – 630 |
| 伸长 (%) | ≥ 26 | ≥ 21 |
| Rough equivalent | ASTM A36 / SS400 | ASTM A572 Gr.50 |
When to Use Q235B
Q235B is the right choice for general fabrication, light frames, fence posts, brackets and indoor structures where loads are moderate. It is cheap, easy to weld and widely available. Browse our Q235B channel, Q235B flat bar 和 Q235B焊管.
When to Step Up to Q355B
Use Q355B for bridges, crane booms, heavy machinery, truck frames and any section where a lighter weight is worth the small premium. 看看我们的 Q355B round bar, Q355B angle 和 Q355B plate.
