Q690D
Data under reviewQ690D is China’s 690 MPa Q&T structural plate, produced by mills such as Wugang and Baowu for cranes, mining trucks and hydraulic supports. Quality D adds a −20 °C impact guarantee over the base grade.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.18 |
| Si | ≤0.50 |
| Mn | ≤2.00 |
| P | ≤0.025 |
| S | ≤0.020 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥690 MPa (≤50 mm) |
| Tensile strength | 770–940 MPa |
| Impact | D grade: 34 J at −20 °C (typ.) |
| Density | 7.85 g/cm³ |
Heat treatment
Delivered quenched and tempered (or TMCP+tempered); do not exceed the mill tempering temperature in fabrication.
Equivalent grades
| Standard | Designation |
|---|---|
| din | S690QL (near) |
| aisi | A514 (near) |
| gb | Q690D (GB/T 1591) |
Compare side by side: Q690D vs S690QL · Q690D vs ASTM A514
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Crane booms, mining dump trucks, coal-mine hydraulic supports, lifting gear.
Processing: High-strength welding practice: matched consumables, controlled preheat/interpass, low heat input to protect HAZ toughness.
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Ask for a quotationVisit NasteelSource: GB/T 1591 published ranges / mill datasheets · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.