Tools · Weld Chemistry

Dilution & Multi-Layer Deposit Blender

Set dilution directly or from bead geometry, then follow the chemistry through each overlay or buttering layer. Every layer is checked for martensite, low ferrite, excess ferrite, and iron pickup.

⚠ Disclaimer: Use at Your Own Risk This tool is provided "as is," for general engineering reference and educational purposes only, with no warranty of any kind. Dilution is modeled with idealized parabolic bead shapes and complete mixing in each pass; real overlays vary with bead overlap, weaving, and torch angle. Ferrite and phase flags use approximate digitizations of the WRC-1992 and Schaeffler diagrams. Jeffrium and Jeffrey Sowards assume no liability for decisions, designs, procedures, or outcomes based on this tool's output. Verify chemistry by analysis of a qualified test coupon. Use of this tool is entirely at your own risk.

Dilution

Base metal

Filler metal

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Bead cross-section

D = Ap / (Ar + Ap) · color shows the filler/base mix

Base metal remaining in each layer

Base-metal fraction in layer k = Dk

Risk flags

Schaeffler phase, WRC-1992 ferrite, and iron pickup

    Chemistry by layer

    Fe is the balance of the listed elements
    How it works

    How weld dilution builds up through layers

    Every pass melts some of what lies beneath it. That share, the dilution, sets the weld chemistry, and in overlays and buttering it carries forward from one layer to the next.

    The math

    DilutionD = Ap / (Ar + Ap)
    One passC = (1 − D)·Cf + D·Cb
    Layer kCk = Cf + Dk·(Cb − Cf)
    Ar, Apreinforcement and penetration areas
    Cf, Cbfiller and base composition
    Dkbase metal left in layer k

    Worked example

    GivenERNiCrMo-3 overlay on carbon steel, D = 20%
    Fe, filler0.7%,  base 98.4%
    Layer 10.7 + 0.20 × 97.7 = 20.2% Fe
    Layer 20.7 + 0.04 × 97.7 = 4.6% Fe
    Result2 layers for Fe ≤ 5%

    At 30% dilution the same overlay needs three layers. A few points of dilution can cost a whole layer.

    More detail

    Assumptions used in this calculator
    • Reinforcement and penetration are parabolic segments of the same width (A = ⅔·w·h), so D = hp / (hr + hp).
    • Every pass mixes completely and melts only the layer directly beneath it, at the same dilution each time. Sideways remelting from overlapping beads is ignored.
    • No element loss or pickup during welding (e.g. carbon, manganese, or nitrogen burn-off).
    • Fe is the balance of the listed elements; unlisted elements (Cu, Ti, W, Co, etc.) are lumped into Fe.
    • Ferrite and phase flags use approximate digitizations of the WRC-1992 and Schaeffler diagrams. WRC-1992 flags apply only within Creq 17-31 and Nieq 9-18.
    • The Fe ≤ 5% and ≤ 10% overlay limits are common values, not universal; use your specification's limit.
    Why parabolic areas?

    A parabolic segment is a good first approximation of both the weld cap and the fusion boundary of a conventional arc bead, with area ⅔·w·h. Because both segments share the same width, dilution simplifies to hp / (hr + hp). Finger-shaped penetration in spray-transfer GMAW or keyhole welding breaks this assumption, so measure the areas from a macro instead.

    What the layer model assumes

    Each pass is assumed to mix completely and to melt only the layer directly beneath it, at the same dilution every time. In real overlays the first layer often runs at higher dilution than later ones, adjacent beads remelt each other sideways, and a deep pass can reach two layers down. Treat the layer count as a minimum and confirm with chemistry taken at the finished overlay thickness.

    Typical dilution ranges
    ProcessTypical D
    Laser cladding, PTA3-10%
    Hot-wire GTAW overlay5-15%
    Strip cladding (ESW)8-12%
    GMAW, SMAW overlay15-35%
    SAW (wire)30-50%
    Root pass, open butt40-70%
    Autogenous GTAW, laser, EB100%
    Stainless to carbon steel: why 309L?

    Diluting 308L with carbon steel pulls the weld metal toward the martensite field of the Schaeffler diagram. The extra Cr and Ni in 309L keep a 20-35% diluted first layer austenitic with a few percent ferrite. Once a 309L buttering layer is in place, later passes can switch to the filler that matches the stainless side.

    References
    • J.N. DuPont and A.R. Marder, “Dilution in single pass arc welds,” Metallurgical and Materials Transactions B 27, 1996, 481–489.
    • J.C. Lippold and D.J. Kotecki, Welding Metallurgy and Weldability of Stainless Steels, Wiley, 2005.
    • D.J. Kotecki and T.A. Siewert, Welding Journal 71(5), 1992, 171-s.
    • A.L. Schaeffler, Metal Progress 56, 1949, 680.
    Related tools
    WRC-1992 / Schaeffler DiagramDissimilar Metal CompatibilityHeat Input Calculator

    Qualifying an overlay or a dissimilar joint?

    Jeffrium builds custom dilution and alloy models around your actual filler heats, bead overlap, and acceptance limits. That includes layer-count optimization, buttering strategy, and chemistry checks before you cut a coupon.

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