Austenitic Stainless Steel for Nuclear Power: 304, 304L & 321
Nuclear Power Austenitic Stainless Steel Grades
JISCO JUDE provides material support for selected nuclear-power stainless steel requirements involving austenitic grades such as 304, 304L and 321. Nuclear-service material acceptance depends on the project code, component classification, procurement specification, inspection requirements, traceability and quality documentation.
| Grade | UNS | EN Reference | Legacy French / Nuclear Reference | Material Characteristic |
|---|---|---|---|---|
| 304 | S30400 | 1.4301 | Z6CN18-10 reference | General Cr-Ni austenitic stainless steel |
| 304L | S30403 | 1.4307 | Z2CN18-10 reference | Low-carbon Cr-Ni austenitic stainless steel for welded applications |
| 321 | S32100 | 1.4541 | Z8CNT18-11 reference | Titanium-stabilized austenitic stainless steel |
Legacy grade designations are provided for technical-reference purposes only. Nuclear-project material requirements must be confirmed against the applicable code edition, project specification and procurement documentation.
Austenitic stainless steels used for selected nuclear-power applications may require more restrictive material controls than conventional commercial stainless steel. Requirements can include controlled chemistry, mechanical properties, surface quality, internal quality, traceability and project-specific inspection.
For certain nuclear applications, cobalt and other residual or trace elements may be subject to tighter project-specific controls. Exact chemical limits should be defined by the applicable nuclear code, material procurement specification and customer requirements rather than assumed from the general stainless steel grade designation.
Material quality should be evaluated through the required production controls, inspection methods, acceptance criteria and documentation. No general webpage statement should be interpreted as guaranteeing the absence of all inclusions, discontinuities or defects.
Austenitic stainless steels may be specified for selected nuclear-power mechanical components, fabricated equipment, piping-related components, vessel internals, supports, storage or handling equipment and other corrosion-resistant applications according to the project design and material specification.
304L is commonly considered where low carbon content and welding performance are important, while stabilized grades such as 321 may be selected for particular temperature, welding or component requirements.
Use in safety-classified or pressure-retaining nuclear equipment requires project-specific material approval, manufacturing controls, inspection and documentation. Suitability cannot be determined from grade designation alone.
Published JISCO Nuclear-Application Material Data
The following values are published JISCO product data for selected 304, 304L and 321 stainless steels associated with nuclear-power applications. The chemistry section lists selected elements rather than a complete standard chemical composition.
| Grade | C (%) | Ni (%) | Cr (%) | N (%) | Ti (%) | B (%) | Co (%) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| 304 | 0.036 | 9.00 | 18.12 | 0.046 | Not reported | Not reported | 0.041 | 275 | 665 | 57.5 |
| 304L | 0.020 | 9.234 | 18.39 | 0.0421 | Not reported | <0.0010 | 0.024 | 255 | 561 | 61 |
| 321 | 0.031 | 9.18 | 17.24 | 0.014 | 0.25 | 0.0007 | 0.18 | 225 | 615 | 53.5 |
Values above are reported JISCO product data and should not be interpreted as universal ASTM, EN, JIS or RCC-M limits, nor as guaranteed values for every order. Final nuclear-project acceptance must be based on the applicable procurement specification, required code edition, certified material test report and project quality documentation.
Cobalt values shown are reported product data only. Nuclear projects may impose project-specific maximum cobalt limits. The reported Co value for each heat must therefore be checked against the applicable procurement specification before material acceptance.
What to Specify for a Nuclear-Power Stainless Steel Inquiry
Nuclear-power stainless steel procurement normally requires more information than a conventional commercial stainless steel inquiry. Material review should be based on the applicable project specification rather than the grade designation alone.
- Material grade: 304, 304L, 321 or other specified grade
- Project material designation: including any RCC-M, customer or project-specific reference where applicable
- Product form: sheet, coil, plate, bar, tube or other required form
- Dimensions: thickness, width, length or other required dimensions
- Applicable code / specification: required nuclear code edition, material procurement specification or customer technical specification
- Chemical controls: any special limits for Co, B or other residual / trace elements
- Mechanical-property requirements: according to the applicable procurement specification
- Inspection requirements: required NDT, surface, dimensional or other inspection
- Traceability: heat number, batch identification and required traceability documentation
- Certification: MTC and any project-specific quality documentation
- Quantity: required pieces, sheets or tonnage
- Destination: country, project location or delivery port
Quality Documentation & Material Traceability
For nuclear-power projects, material documentation and traceability may be as important as the stainless steel grade itself. Required records depend on the applicable project code, component classification and customer procurement specification.
Where specified, documentation may include material test certificates, heat-number traceability, chemical-analysis results, mechanical-property test results, inspection records and other project-specific quality documents.
Any requirement for enhanced trace-element control, additional testing, third-party inspection or project-specific certification should be identified before quotation and production.
Availability of specific nuclear-project documentation or qualification should be confirmed for the individual order. This webpage should not be interpreted as evidence that every JISCO JUDE stainless steel product is automatically qualified for nuclear service.
Before placing an order:
Please provide the applicable nuclear code, material procurement specification and required documentation for technical review. JISCO JUDE will evaluate material availability and documentation requirements against the specific inquiry rather than relying only on the commercial grade designation.
Need Stainless Steel for a Nuclear-Power Project?
Send your material grade, product form, dimensions, quantity, applicable code or procurement specification, chemical-control requirements, inspection requirements and delivery destination. JISCO JUDE can review material and documentation requirements for your project.
Nuclear-Power Stainless Steel FAQ
Is 304L automatically a nuclear-grade stainless steel?
No. 304L is a standard stainless steel grade, but suitability for a nuclear project depends on the applicable code, material procurement specification, component classification, chemical controls, manufacturing route, inspection, traceability and required quality documentation.
Why can cobalt content be important in nuclear stainless steel?
Some nuclear applications may impose project-specific limits on cobalt and other residual or trace elements. The required limit should be taken from the applicable project specification rather than assumed from the general 304, 304L or 321 grade designation.
Why is boron content shown for some nuclear-application materials?
Boron may be monitored or controlled for selected nuclear applications. Any required boron limit should be specified by the project or procurement specification. The values shown on this page are reported JISCO product data rather than universal nuclear-code limits.
What is the difference between commercial 304L and nuclear-project 304L?
The basic stainless steel grade may be the same, but a nuclear project can impose additional requirements for chemistry, residual elements, mechanical properties, inspection, traceability, documentation and quality assurance.
Can JISCO JUDE provide material test certificates?
Material documentation requirements should be stated with the inquiry. Available MTC, chemical-analysis, mechanical-property and other inspection documentation can be reviewed according to the specific material and project requirements.
Does JISCO JUDE guarantee RCC-M compliance for every 304L or 321 order?
No general webpage statement should be interpreted as guaranteeing RCC-M or other nuclear-code compliance for every order. The applicable code edition and procurement specification must be reviewed for the specific material, product form and project.
What information should I provide for a nuclear stainless steel inquiry?
Please provide the material grade, product form, dimensions, quantity, applicable code or material procurement specification, chemical-control requirements, mechanical-property requirements, inspection and traceability requirements, required documentation and destination.
