Castings

Cor-Ten

Conversion table of produced steels. We prefer to supply final product according to Chomutov marking. On special customer´s request is possible to supply castings according to other standard.

ČSN 42 2709 (Mn steel)

Chemical composition in percents

Castings are delivered as normalized (+N) or normalized and tempered (+NT). Hardening treatment of this quality is not performed.

Mechanical properties and values

Weldability

Guaranteed under specific conditions – preheating to 250°C. After welding, it is recommended to anneal at 600-630°C for the stress relieving.

Machinability

Very good when normalized and tempered. Good in heat-treated condition.

Application

For parts subjected to greater stresses with higher toughness, for example track shoe of tractors, etc. The steel has a good hardenability and is capable even for surface flame hardening.

ČSN 42 2712 (Mn steel)

Chemical composition in percents

Castings are delivered as normalized and tempered (+NT). Considering intended use, this steel is not heat-treated exceptionally.

Mechanical properties and values

Weldability

Guaranteed – up to a thickness of 25 mm. Guaranteed under specific conditions – over 25 mm in thickness preheating to 200°C. After welding, it is recommended to anneal at 590-620°C for the stress relieving.

Machinability

Very good.

Application

For cast parts of steam boilers and turbines, pressure tanks, steam and water pipes, plumbing fittings, highly stressed machine parts and welded pieces up to 450°C operating temperatures where high toughness is required.

ČSN 42 2719 (Si steel)

Chemical composition in percents

Castings are delivered as normalized and tempered (+NT). Hardening treatment of this quality is not performed.

Mechanical properties and values

Weldability

Good – preheating to 350°C. After welding, the casting must be annealed at 620-650°C for the lowering of stress. After annealing the castings must be allowed to cool in the furnace. Welding or welding up of flaws in critical and exposed places is not recommended.

Machinability

Good, by a lowered cutting speed.

Application

The steel is intended for higher pressures and stresses, e.g. gears of lower weight, ring gear, etc. It is not suitable for surface flame hardening.

G42CrMo4 (Cr-Mo steel)

Chemical composition in percents

Castings are delivered as normalized (+N).

Weldability

Good – preheating to 350°C. After welding, the casting must be normalized is necessary. Welding or welding up on functionally exposed places is not recommended.

Machinability

Good – as normalized
Difficult – when is hardening treated

Application

As normalized for gear and travel wheels of cranes and other highly stress machine parts.

VTS

The castings are usually not intended for cutting operation, but for direct use. They are delivered as hardening treated (QT). Exceptionally soft annealed (+A).

Mechanical properties and values

*) in condition soft annealed
**) in condition hardened treated

Weldability

Good under specific conditions – preheat to 150°C. Apply short interrupted weld beads. Forge immediately weld metal. Ensure very slow cooling. The material is not recommended to welding.

Application

For forms for injection moulding.
For its high strength and toughness, the steel is also suitable for excavators teeths and castings where is required high resistance to the dynamic forces connected with contemporary impacts and high abrasion.
The steel is greatly self-hardenable on air.

VP-7

Mechanical properties and values

Weldability

Good to difficult – preheating to 250°C is required.
After welding or welding up of the surface flaws, it is necessary to provide a slow cooling down or to be again heat-treatment.
This steel is not intended for welding.

Machinabilityt

Very difficult. When machining is necessary, soft annealing is more preferable. Subsequently heat-treated.

Application

Very suitable for the production of excavator teeth, socket of bucket, rock blades, etc. Wherever increased resistance to plastic deformation under simultaneously impact of dynamic forces and impact and resistance to abrasion is required. The steel is eligible for local thermal reprocessing of castings parts to a higher hardness.

ON 42 2833 (Eutectoid Cr-W Steel)

Chemical composition in percents

The castings are delivered only as soft annealing (+A) for using to cutting operation.
The castings, that are not intended to cutting operation, but used directly, are delivered as hardened (+QT) to lower values. The smaller castings can be hardened to higher values only on agreement.

Mechanical properties and values

Hardening treatment at lower values is carried out by air hardening, at higher values by oil hardening. The foundry has not its own oil bath at disposal.

+) as soft annealed
*) in condition hardened to lower values
**) in condition hardened to higher values

Weldability

Difficult. The welding is not recommended!

Machinability

Difficult in soft annealed condition. In hardened condition is possible only by grinding.

Application

Basically it is a tool steel with a wide application for simple, bulky cast tools to be used for cold and warm works. The rolls for rolling mills up to 300 mm diameter, dies, punches, blades for hydraulic shears for scrap, tools for pressure castings does not achieve the level of those in the formed steel.
The mechanical properties allow application in production of various parts under wear resistant conditions.
Higher values than those given above are not recommended., although the material is capable to achieve them. Such castings could be destructed.