Steel 30Q130-SRA
Heat-treated state
EN 30Q130 · ASTM A876 · JIS 30P105
SRA = stress-relief annealed after shearing/forming
Pick after slitting, punching or bending of laminations to recover the core loss lost to cutting stresses.
Values for the SRA condition
What is 30Q130-SRA?
30Q130-SRA is 30Q130 heat treated to SRA — pick after slitting, punching or bending of laminations to recover the core loss lost to cutting stresses. 30Q130-SRA has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 88% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi). 30Q130-SRA has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,470°C (2,678 °F).
Limitations
- Low stiffness — 120 GPa (17.4 Msi), worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Poor heat conductor — 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades
- Low strength — 290 MPa (42.1 ksi), worse than 88% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
30Q130-SRA properties
Typical room-temperature values for 30Q130-SRA; 6 are specific to this condition. Other listed values are 30Q130 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
30Q130-SRA has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical11
30Q130-SRA has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 88% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
Thermal6
30Q130-SRA is rated for continuous service to 200°C (392 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
30Q130-SRA conducts electricity at 3.6 % IACS, worse than 85% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 30Q130-SRA takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 15%.
Manufacturability7
30Q130-SRA's machinability is fair (40/100, worse than 77% of steel grades); weldability fair (35/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 30Q130-SRA
Is 30Q130 easy to machine?
Normally slit, sheared or laser/wire cut rather than machined; carbide or coated tooling and very sharp punch clearances (2–5 % of thickness) are essential to limit burrs that short laminations.
Can 30Q130 be welded?
TIG/laser tacking of core clamps is possible but the heat-affected zone loses magnetic quality — keep welds out of the flux path and stress-relief anneal if practical.
Can 30Q130 be formed, bent or molded?
Highly anisotropic and brittle; limited to shearing, mitre cutting and the gentle bends used in wound (unicore) transformer cores, always with flux parallel to the rolling direction.
What surface finishes work on 30Q130?
Supplied with an inorganic phosphate C-5 insulating coating; do not paint, plate or anodize — post-cut cores are usually stress-relief annealed then varnish/resin impregnated.
30Q130 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Siraises resistivity, lowers eddy-current loss | 2.8 – 3.4 | 3.1 |
| Cdecarburised in finished product to avoid magnetic ageing | ≤ 0.01 | 0 |
| Mn | 0.03 – 0.2 | 0.08 |
| SMnS inhibitor route residual | ≤ 0.01 | 0 |
| P | ≤ 0.03 | 0.01 |
| Alacid-soluble Al (AlN inhibitor) | ≤ 0.03 | 0.01 |
| N | ≤ 0.01 | 0 |
| Cuinhibitor/residual, route dependent | ≤ 0.3 | 0.05 |
| Fe | balance |
30Q130-SRA — frequently asked
What is 30Q130-SRA used for?
30Q130-SRA is typically used for power transformer cores, distribution transformer cores, large reactors and instrument transformers. In short: lowest core loss oriented steel; transformer core grade; directional magnetic properties only.
What is the yield strength of 30Q130-SRA?
30Q130-SRA has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 88% of steel grades.
Is 30Q130-SRA easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Normally slit, sheared or laser/wire cut rather than machined; carbide or coated tooling and very sharp punch clearances (2–5 % of thickness) are essential to limit burrs that short laminations.
Can 30Q130-SRA be welded?
With care — weldability is rated fair (35/100). TIG/laser tacking of core clamps is possible but the heat-affected zone loses magnetic quality — keep welds out of the flux path and stress-relief anneal if practical.
What surface finishes work on 30Q130-SRA?
Supplied with an inorganic phosphate C-5 insulating coating; do not paint, plate or anodize — post-cut cores are usually stress-relief annealed then varnish/resin impregnated.
Can 30Q130-SRA be formed, bent or molded?
Highly anisotropic and brittle; limited to shearing, mitre cutting and the gentle bends used in wound (unicore) transformer cores, always with flux parallel to the rolling direction.
What is the maximum service temperature of 30Q130-SRA?
30Q130-SRA is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10107 Grain-oriented electrical steel strip and sheet delivered in the fully processed state — CEN (2014)
- ASTM A876 / A343 Grain-oriented electrical steel, fully processed types & core loss test — ASTM (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels (Electrical Steels) — ASM International (1990)
- Grain-oriented electrical steel product catalogue — Baosteel (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.