30CrMnSiA
Data verified30CrMnSiA is a Chinese high-strength structural steel (GB/T 3077, of the Soviet 30KhGSA lineage) that reaches 1080 MPa class strength with a lean Si-Mn-Cr chemistry. It has no direct AISI/JIS equivalent and is widely used in Chinese aviation, fasteners and welded high-strength structures.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.28–0.34 |
| Si | 0.90–1.20 |
| Mn | 0.80–1.10 |
| P | ≤0.035 |
| S | ≤0.035 |
| Cr | 0.80–1.10 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Tensile strength | ≥1080 MPa (GB/T 3077 reference Q&T) |
| Yield strength | ≥835 MPa (reference) |
| Density | 7.85 g/cm³ |
| Hardenability | High for its alloy level (Si-Mn-Cr synergy) |
Heat treatment
Quench 880 °C oil; temper 450–550 °C class. Watch decarburization from the high silicon during heating.
Equivalent grades
| Standard | Designation |
|---|---|
| gb | 30CrMnSiA (GB/T 3077) |
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: High-strength bolts, aviation fittings, welded structures, shafts and springs.
Processing: Weldable with controlled procedure despite the strength level; protect against decarburization in heat treatment.
FAQ
- Is there a Western equivalent of 30CrMnSiA?
- No direct one — the high-silicon Si-Mn-Cr concept is a Chinese/Russian design. Substitution candidates are chosen by property (e.g. 4340 or 30CrMnSiNi2A class), never by chemistry alone.
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Ask for a quotationVisit NasteelSource: GB/T 3077 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.