Steel 30P105-SRA
Heat-treated state
EN 30P105
SRA = stress-relief annealed after shearing/winding
Pick after cutting, punching or core winding to recover the 5–15 % core-loss increase caused by cutting and bending stresses.
Values for the SRA condition
What is 30P105-SRA?
30P105-SRA is 30P105 heat treated to SRA — pick after cutting, punching or core winding to recover the 5–15 % core-loss increase caused by cutting and bending stresses. 30P105-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). 30P105-SRA has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,480°C (2,696 °F).
Limitations
- Low stiffness — 120 GPa (17.4 Msi), worse than 99% of steel grades
- Poor heat conductor — 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades
- Limited service temperature — 200°C (392 °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
30P105-SRA properties
Typical room-temperature values for 30P105-SRA; 5 are specific to this condition. Other listed values are 30P105 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
30P105-SRA has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,480°C (2,696 °F).
Mechanical11
30P105-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
30P105-SRA is rated for continuous service to 200°C (392 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
30P105-SRA conducts electricity at 3.6 % IACS, worse than 85% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 30P105-SRA takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 20%.
Manufacturability5
30P105-SRA's machinability is fair (40/100, worse than 77% of steel grades); weldability fair (40/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 30P105-SRA
Is 30P105 easy to machine?
Normally slit, punched or mitre-sheared rather than machined; use sharp carbide tooling and tight clearance (≈5 % of thickness) to keep burrs under ~20 µm, as burrs short-circuit laminations and raise loss.
Can 30P105 be welded?
Fusion welding (TIG/laser) is possible for core clamping or strip joining but destroys the Goss texture and coating in the heat-affected zone, so keep welds off the flux path.
Can 30P105 be formed, bent or molded?
Cold formability is poor and strongly anisotropic — restrict to gentle bending along the rolling direction and core winding, then stress-relief anneal at ~800 °C in a protective atmosphere.
What surface finishes work on 30P105?
Supplied ready-coated (glass film + phosphate); avoid pickling, abrasive cleaning or heavy handling that damages the insulation, and re-varnish only where coating loss is unavoidable.
30P105 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 |
|---|---|---|
| SiGoss-textured 3% silicon iron | 2.9 – 3.4 | 3.15 |
| Cafter decarburization anneal | ≤ 0.01 | 0 |
| Mn | 0.03 – 0.15 | 0.08 |
| SMnS/AlN inhibitors largely removed in purification anneal | ≤ 0.01 | 0 |
| P | ≤ 0.03 | 0.01 |
| Alacid-soluble Al for AlN inhibitor (Hi-B route) | ≤ 0.04 | 0.02 |
| N | ≤ 0.01 | 0 |
| Cuoptional inhibitor addition | ≤ 0.15 | 0.05 |
| Fe | balance |
30P105-SRA — frequently asked
What is 30P105-SRA used for?
30P105-SRA is typically used for distribution transformer cores, power transformer cores, wound (unicore) transformer cores, reactor cores, instrument and current transformer cores and welding transformer cores. In short: low-loss transformer core steel; JIS grain-oriented grade; strongly directional properties.
What is the yield strength of 30P105-SRA?
30P105-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 30P105-SRA easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Normally slit, punched or mitre-sheared rather than machined; use sharp carbide tooling and tight clearance (≈5 % of thickness) to keep burrs under ~20 µm, as burrs short-circuit laminations and raise loss.
Can 30P105-SRA be welded?
With care — weldability is rated fair (40/100). Fusion welding (TIG/laser) is possible for core clamping or strip joining but destroys the Goss texture and coating in the heat-affected zone, so keep welds off the flux path.
What surface finishes work on 30P105-SRA?
Supplied ready-coated (glass film + phosphate); avoid pickling, abrasive cleaning or heavy handling that damages the insulation, and re-varnish only where coating loss is unavoidable.
Can 30P105-SRA be formed, bent or molded?
Cold formability is poor and strongly anisotropic — restrict to gentle bending along the rolling direction and core winding, then stress-relief anneal at ~800 °C in a protective atmosphere.
What is the maximum service temperature of 30P105-SRA?
30P105-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
- JIS C 2553 Grain-oriented magnetic steel sheet and strip — JSA (2019)
- GB/T 2521.2 Cold-rolled grain-oriented electrical steel strip (30Q105 equivalent) — SAC (2016)
- Grain-oriented electrical steel (Hi-B) product data — Nippon Steel (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (magnetically soft materials) — ASM International (1990)
- ASM Handbook Vol.2 / Metals Handbook — Special-Purpose Materials, Si-Fe alloys — ASM International (1990)
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.