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Steel foundry in Klavreström, Sweden. Stainless and acid-proof castings, from pattern to certified delivery.

Yes, we cast that.

GX5CrNiMo19-11-2 · 1.4408 to EN 10283/10213

Austenitic CrNiMo, acid-proof

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Two founders in protective suits pour molten steel from the ladle into a sand mould
Pouring in the casting hall, Klavreström

Customers

Our castings sit inside pumps, valves, paper machines and vessels built by Sulzer, Alfa Laval, Xylem, Valmet, Somas, Stafsjö, Cellwood, Humphree, Log Max, Olvondo, Silver Weibull, Turab and FFS.

What they share is high demands on surface finish and pressure tightness.

55 designations in 31 production groups

Stainless and acid-proof is our speciality. Alloys in the same group share a composition window, so an EN grade and its ASTM equivalent are poured from the same melt. Pick a designation to look it up.

  • Austenitic stainless

    1 group

  • Austenitic CrNiMo, acid-proof

    4 groups

  • Superaustenitics

    6 groups

  • Duplex and superduplex

    8 groups

  • Martensitic

    2 groups

  • Precipitation hardening

    2 groups

  • Carbon steel and 13Cr

    3 groups

  • White iron, high-chromium and manganese steel

    5 groups

Can't find your grade? To order, we cast most common steel grades.

The full alloy programme

From sand mould to inspected casting

We cast by gravity in single-use sand moulds. Every part gets a new mould, which is broken apart to release the casting. Everything happens on one site, which is why lead times stay short.

  1. Moulding the CO₂ method

    Core box for a pump impeller, and finished impeller cores
    Pattern and core box. The pattern forms the outside of the casting, the core its inside.
    +2 %How much larger the pattern is made. The casting contracts as it cools.
    Open sand mould with the cavity and gating system cut into the sand
    New sand, with zircon sand next to the pattern, gives fine surfaces and good dimensional accuracy.
    The spirit in the coating is burned off a mould half
    The spirit in the coating is burned off, leaving a protective layer.
    The mould halves are closed
    Mould halves and cores are assembled.
  2. Casting low and full, without air or slag

    Molten steel is poured from the ladle into the mould
    Pouring. The gating system keeps the flow calm all the way into the mould.
    Poured mould with the alloy number written in the sand
    A poured mould. The alloy number is written in the sand.
    −10 %How much the steel shrinks as it solidifies. The feeders top it up meanwhile.
    Feeder on a casting with clear solidification shrinkage at the top
    The shrinkage shows in the feeder, not in the casting.
  3. Finishing fettling, heat treatment, blasting

    Valve body in the fettling booth, with grinders and a welder
    Fettling booth. Gating system and feeders are cut away, the casting is deburred.
    Pump casing on the blasting table
    Blasting with a stainless medium removes scale before delivery.
Molten steel is poured from the ladle in the casting hall as flames rise from the freshly cast moulds
The casting hall in Klavreström

The foundry in brief

Method
Gravity casting in single-use sand moulds. Moulds are made by the CO₂ method.
Materials
Stainless and acid-proof steel. Also duplex, martensitic, carbon steel, white iron and manganese steel.
Heat treatment
Our own furnace, fitted with a recorder. Every cycle can be followed and verified afterwards.
Delivery
As-cast blank or fully machined part, blasted with a stainless medium.
Certificates
ISO 9001:2015PDF, TÜV to PEDPDF, Bureau Veritas Mode II
Company
Formed in 1998 through the merger of Klarviks Stålgjuteri and Klafreströms Stål. Part of Opima.

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