Vacuum induction degassing unit: VID furnace that melts and degasses steel under vacuum, then pours in air

01

Choose between a VID furnace and a full VIM casting furnace

ALD Vacuum Technologies describes its VID furnaces as compact, simplified vacuum induction melting furnaces for charge weights up to 30 t, for steels and other alloys needing melting, liquid metal refining and degassing in vacuum while still allowing the melt to be poured in air. It lists melting and liquid metal treatment in vacuum or under inert gas with pouring in air, temperature control, vacuum refining, decarburisation and slag treatment, and a simplified design with no mould chamber, and offers sizes from 1 to 30 t. [1]

ALD names three variants: VID for pouring in ambient air, VID Pro for pouring under protective gas, and VID Oxy for carbon removal by introducing oxygen into the melt through a lance with slag treatment. It presents VID as an alternative to ladle-furnace and vacuum-degassing (LF/VD) systems for heats up to 30 t, letting mini mills and foundries make vacuum-treated steels in one step and removing the risk of metal freezing during liquid metal transfer; grades it lists include tool and high-speed steels, heat-treatable, austenitic and martensitic steels, steels for energy technology and Ni-base and Co-base alloys. [1]

Where the melt must also be cast under vacuum, ALD's VIM 100–4000 line covers chamber-type and compact VIM-VIDP furnaces with melt capacities of 1–30 t, producing ingots, electrodes for ESR or VAR remelting and bar-sticks for precision casting and powder; its variants include front-door (VIM-F), side-door (VIM-S), ladle (VIM-L) and rope-tilting crucible (VIM-R) designs. ALD dates the first industrial-scale VIM furnace built by its parent company to 1928 in Hanau. [2]

Give the supplier the alloys and grades, heat size in tonnes, charge materials, target oxygen, nitrogen, hydrogen and carbon levels, whether pouring in air, under protective gas or in vacuum is required, the downstream route (ingot, electrode, bar-stick), and power and cooling-water available.

02

Judge the metallurgical result: oxygen, nitrogen and inclusions

A 2025 Materials study compared H13 hot-work die steel made by electroslag remelting (ESR) with steel made by vacuum induction melting followed by vacuum arc remelting (VIM+VAR), melted at 1,450 °C in the VIM and refined at 1,600 °C in the VAR. The VIM+VAR steel had 0.0008 wt% total oxygen and 0.001 wt% nitrogen against 0.0016 wt% and 0.015 wt% for the ESR steel, and 0.005 wt% phosphorus against 0.016 wt%. [3]

The same study reports a fatigue strength at 10⁷ cycles of 1,040 MPa for the VIM+VAR steel against 967 MPa for the ESR steel, a mean inclusion size about 55% and a maximum inclusion size about 44% of the ESR steel's, with oxides or oxide-sulfide composites as the main crack-initiation sites. [3] Editorial calculation: 0.0008 wt% is 8 ppm and 0.001 wt% is 10 ppm; 1,040 ÷ 967 ≈ 1.075, the about 7.5% fatigue gain the authors report.

Editorial note: these results are for a VIM+VAR route on one steel, not for a VID furnace alone; ask the supplier for oxygen, nitrogen and hydrogen results from its furnaces on grades like yours.

03

VID, VID Pro, VID Oxy and VIM-VIDP furnace designs

The designs below come from one furnace builder's published range.

04

Induction crucible, vacuum chamber, pumping set and tilting gear of a VID furnace

05

Vacuum levels, ladle capacity, coil frequency and pumping speed of the furnace

06

Send the grades, heat size and pouring route together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Grades: [steels; Ni/Co alloys]
Heat size: [t]
Targets: [O; N; H; C]
Pouring: [air; protective gas; vacuum casting]
Products: [ingots; electrodes; bar-sticks]
Utilities: [power; cooling water; gases]

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