- EN / Grade
- 1.4550
- Other designations / UNS
- 347 / X6CrNiNb18-10
UNS S34700 - Family
- Austenitic
Purpose of stabilisation
Niobium binds carbon to limit chromium-carbide formation at grain boundaries during certain thermal exposures. This differs from selecting a low-carbon grade. Stabilisation does not mean every weldment can be accepted without further treatment or that every high-temperature application is suitable.
Choosing between 321 and 347
321 uses titanium and 347 uses niobium for stabilisation. The project product specification, welding consumables and fabrication sequence influence the choice. Similar applications do not justify changing the material on a drawing without a project-specific equivalence assessment.
Temperature alone is not enough
Duration, thermal cycling and mechanical stress matter together in a loaded hot component. Oxidation resistance and creep strength are different properties. Include loading conditions and whether the product is sheet, tube or bar alongside the temperature range so that finish and delivery condition can be clarified.
Typical application areas
Expansion components, exhaust and hot-process parts, chemical equipment.
Product and cutting options
Share the section and dimensions you require for this grade. Availability is assessed for each request; the catalogue does not represent live stock.
What to specify in your enquiry
- Grade designation and applicable material standard
- Section, finished dimensions and machining allowance
- Quantity, delivery condition and certificate requirements
Frequently asked questions
Can I request 1.4550 in cut lengths?+
Share your required section, dimensions and quantity. Our team will assess suitable supply and cutting options for the specific grade.
Are the listed grade designations interchangeable?+
Designation systems can overlap, but they do not make every specification identical. Use the exact standard and certificate requirements defined by your project.