③ 标准/对比页
Q390 Steel Plate: Properties That Go Into Spec Sheets
Q390 sits one clear step above the Q355 family in GB/T 1591-2018, trading a little formability for 390 MPa of guaranteed yield. This page collects the properties that actually go into specification sheets — yield, tensile, impact tiers, delivery condition — with numbers anchored to the standard.
Headline MechanicalsIn the base range (up to 16 mm), Q390 guarantees a minimum yield of 390 MPa and a tensile band of 490–650 MPa. Above 16 mm the yield requirement steps down through the standard's thickness tables, so always pair the grade with the thickness list when requesting quotations — a 40 mm Q390 plate does not carry the same floor as a 10 mm one.
Impact TiersLike the rest of the GB/T 1591 family, Q390 comes in B, C, D and E qualities: Charpy KV2 of at least 34 J at +20 ℃, 0 ℃, −20 ℃ and −40 ℃ respectively. Winter-service equipment normally specifies D; E is reserved for the coldest duty. The quality letter costs a little and saves a lot of review time.
Delivery and FabricationSupply condition is hot-rolled, controlled-rolled or normalized depending on thickness and agreement. Elongation runs at 20 % typical, and the grade keeps sound weldability under normal low-hydrogen practice. Z-quality levels can be added by agreement where through-thickness stress is designed into the joints.
Where Q390 Earns Its PlaceTypical duty: construction machinery structural members, lifting equipment, towers and high-load vehicle beams — applications where Q355 feels under-specified but the step to Q460 is not yet justified. It is the practical middle rung of the high-strength ladder.
OrderingYunhao supplies Q390B/C/D/E in 8–80 mm, widths 1500–3200 mm, MOQ 25 t, 15–30 days from Tianjin or Qingdao, with mill test certificates stating grade, quality letter and results. Bundle Q390 with Q460 or Q550 lines on the same shipment to consolidate freight.
| Item | Q390 (GB/T 1591-2018) |
|---|---|
| Yield ReH (≤16 mm) | ≥390 MPa |
| Tensile Rm | 490–650 MPa |
| Charpy KV2 | ≥34 J (B/C/D/E: +20/0/−20/−40 ℃) |
| Elongation A | ≥20 % typical |
| Thickness (Yunhao) | 8–80 mm |
| Quality letters | B / C / D / E |