Subject: High Strength Structural Steel Plates in the Quenched and Tempered Condition
The steel is typically delivered in the Quenched and Tempered (Q&T) condition (known as "Tiao Zhi" in Chinese), which provides high strength through heat treatment.
Melting Analysis (Typical Limits %): The standard restricts elements to ensure weldability. While specific limits vary by grade, the general trends are:
| Element | Typical Limit (Max %) | Purpose | | :--- | :--- | :--- | | Carbon (C) | 0.12% – 0.20% | Lower carbon improves weldability. | | Silicon (Si) | 0.60% | Deoxidizer. | | Manganese (Mn) | 1.00% – 1.70% | Strengthens ferrite. | | Phosphorus (P) | 0.025% (for Grade E) | Impurity restricted for toughness. | | Sulfur (S) | 0.015% (for Grade E) | Impurity restricted to prevent cracking. | gb t 16270 pdf
Note: Higher grades (Q690) often require micro-alloying elements like Nb (Niobium), V (Vanadium), Ti (Titanium), and sometimes Cr (Chromium) or Mo (Molybdenum).
GB/T 16270 specifies the technical requirements for high strength structural steel plates.
If you are an engineer used to ISO, EN, or ASTM standards, you will appreciate how GB/T 16270 aligns with global norms. Your GB/T 16270 PDF will often serve as a cross-reference document. Subject: High Strength Structural Steel Plates in the
| GB/T 16270 | International Equivalent | Notes | | :--- | :--- | :--- | | Q460 | S460Q (EN 10025-6), A514 Grade B (ASTM) | Very close match. | | Q550 | S550Q (EN 10025-6) | Direct mechanical equivalence. | | Q690 | S690Q (EN 10025-6), ASTM A514 Grade Q | The most common interchangeable grade. | | Q960 | S960Q (EN 10025-6) | Niche applications; careful of CEV differences. |
Key Difference: Chinese standards often allow slightly wider tolerances on thickness dimensions but have stricter rules for low-temperature impact testing.
For high-strength steels, weldability is a primary concern. The PDF stipulates maximum limits for: | | Silicon (Si) | 0
This standard specifies the classification, code, dimension, shape, weight, technical requirements, test methods, inspection rules, packaging, marking, and quality certificates for high-strength structural steel plates and strips.
It applies to steel plates with a thickness of 3mm to 100mm used in structures such as bridges, buildings, offshore platforms, and other engineering applications requiring high strength and good weldability.