Stainless Steel 1.4807-SA (Solution/diffusion annealed)

1.4807-SA is typically used for furnace fixtures, radiant tubes and kiln components. In short: nb-stabilized HT casting; best creep strength here; cast only, no forming.

1.4807-SA has a typical yield strength of 225 MPa (32.6 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 99% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.

Not especially — machinability is rated poor (26/100, worse than 84% of stainless steel grades). Difficult: use rigid setups, sharp carbide or ceramic tooling, low speed with heavy positive feed to cut under the hard carbide network and avoid work-hardened glazing; grinding is often preferred for finish surfaces.

With care — weldability is rated fair (45/100). Weld with matching 35Ni-18Cr-Nb filler or a Ni-base (ERNiCr-3) consumable, preheat 150–250 °C for heavy sections, low heat input and slow cooling; aged/carburized ex-service material should be buttered or replaced rather than welded directly.

Shot blast or pickle to remove casting scale; not anodizable, and paint/plating is pointless in service — the alloy relies on its own adherent Cr-Si oxide scale, so parts are usually left bare or aluminized for extreme carburizing duty.

Cast only — sand, investment or centrifugal casting with generous risering and fillets; no cold forming, and hot straightening should be done above ~1000 °C.

1.4807-SA is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

AC is the default condition — standard delivery condition for furnace fixtures, retorts and radiant-tube components; no heat treatment required for high-temperature service. Aged: reference condition for repair or re-use assessment: secondary carbide precipitation raises strength but severely lowers RT ductility and weldability. Yield strength is 240 MPa in AC versus 300 MPa in Aged.