Castings

Heatresistant

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.

Some types of castings are also roughted or machined according to our possibilities.

ČSN 42 2934 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered stabilizing annealing (+SR).

Mechanical properties and values

*) The mechanical values Z, KC and K are not decisive at room temperature. This steel is intended for the stress under high temperatures up to 1000°C. With an increase in the amount of carbon the values of Rm rise up to by 200 N/mm2; Re by up to about 100 N/mm2. The values of A and KC however decline. The tendency to rise remains preserved in austenitized condition, even after long term annealing at 650-800°C.

The highest permitted operating temperature

• permanent load: ≤ 950°C
• short-term load: ≤ 1000°C

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 950°C
  > max. 2 g S/m³ =< 930°C
  < min. 2 g S/m³ =< 850°C
• reducing + carburizing
  sulfur-free =< 900°C
  > max. 2 g S/m³ =< 850°C
  < min. 2 g S/m³ nevyhovující

Yield point R_p (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 41 N/mm²
• 800°C >= 20 N/mm²
• 900°C >= 9 N/mm²

Weldability

Good. Up to a thickness of 25 mm preheating is not necessary. Over 25 mm preheat to at least 150°C. After welding, cool in water. New annealing is not necessary.

Machinability

Good to difficult.

Application

Mechanically stressed parts of continuous and chamber furnaces (guide angles), conveyor rollers, rails in low temperature zones, covers of shaft furnaces, etc. The vessels for salt bath where the melt temperature is lower. The material is not to be used as corrosion resistant, but as scale resistant.

ČSN 42 2936 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered stabilizing annealing (+SR).

Mechanical properties and values

*) The mechanical values Z, KC and K are not decisive at room temperature. This steel is intended for the stress under high temperatures up to 1100°C. With an increase in the amount of carbon the values of Rm increase by up to about 200 N/mm2; Re by up to about 100 N/mm2. The values of A and KC, however, decline. The tendency to rise remains preserved in austenitized state, even after long term annealing at 650-800°C.

The highest permitted operating temperature

• permanent load: =< 1050°C
• short-term load: =< 1100°C
• The heat resistance and heat load can be increased by approximately 50°C when C-content is higher up to 0.55% and Si-content up to 2.50%. However in the same time the resistance to brittleness is getting lower in the temperature range 600-900°C. Such requirement is possible only on agreement between the buyer and manufacturer.

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 1100°C
  > max. 2 g S/m³ =< 1100°C
  < min. 2 g S/m³ =< 1050°C
• reducing + carburizing
  sulfur-free =< 1030°C
  > max. 2 g S/m³ =< 1030°C
  < min. 2 g S/m³ nevyhovující

Yield point R_p 1 (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 44 N/mm²
• 800°C >= 22 N/mm²
• 900°C >= 11 N/mm²
• 1000°C >= 4,5 N/mm²

Weldability

Good. Up to a thickness of 25 mm preheating is not necessary. Over 25 mm preheat to at least 200°C. After welding, cool in water. New annealing is not necessary.

Machinability

Good to difficult

Application

Mechanically stressed parts of metallurgical furnaces, rails, annealing retorts and pots, conveyor chain links, etc.
Not applicable at temperatures under 900°C the steel is getting brittle. The material is not to be used as corrosion resisting, but scale resisting.

ČSN 42 2944 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered stabilizing annealing (+SR).

Mechanical properties and values

*) The mechanical values Z, KC and K are not decisive at room temperature. This steel is intended for the stress under high temperatures up to 1200°C.

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 1200°C
  > max. 2 g S/m³ =< 1170°C
  < min. 2 g S/m³ =< 1040°C
• reducing + carburizing
  sulfur-free =< 1050°C
  > max. 2 g S/m³ =< 1030°C
  < min. 2 g S/m³ =< 1070°C

Yield point R_p 1 (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 31 N/mm²
• 800°C >= 15 N/mm²
• 900°C >= 7 N/mm²
• 1000°C >= 2,5 N/mm²

Weldability

Difficult. It is better to avoid welding connections – this involves certain difficulties. It is necessary to preheat the steel to minimum 400°C. At deep weldings up it is better to use the proper root electrode.
The covering patch is to be done by short weld beads, to be hammered immediately. New annealing is necessary after welding.

Machinability

Good to difficult

Application

For the castings subjected to the most temperatures and mechanical stress. Parts of annealing, roasting, harden furnaces in reduction atmospheres, where SO2 is present. In pots for salt baths with high temperatures of melt. At temperatures under 900°C, the steel is getting brittle. The brittleness disappears at temperatures over 950°C

ČSN 42 2951 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered as austenitized (+AT).

Mechanical properties and values

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 1120°C
  > max. 2 g S/m³ =< 1080°C
  < min. 2 g S/m³ =< 1050°C
• reducing + carburizing
  sulfur-free =< 1080°C
  > max. 2 g S/m³ =< 1000°C
  < min. 2 g S/m³ =< 950°C

Yield point R_p 1 (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 62 N/mm²
• 800°C >= 37 N/mm²
• 900°C >= 19 N/mm²
• 1000°C >= 9 N/mm²
• 1100°C >= 2 N/mm²

Weldability

Difficult. The steel is not suitable for welding. In unavoidable situations, it is necessary to preheat the steel to 150°C. It is necessary to weld by short interrupted weld beads and immediately heat forge with hammer.
The resistance to carburization is reduced in welded areas. New austenization is necessary after welding.

Machinability

Good

Application

The steel is resistant to carburization in waste gas environments containing SO2. It has high mechanical values in high temperatures. It is suitable for grates of continuous and chamber case hardening furnaces and their constructions. For transport hooks and for the jigs of pit cementation furnaces with long service life. For parts of walking beam furnaces with varying temperatures, etc.
When used in temperatures under 900°C, the steel is getting brittle. The brittleness disappears at temperatures over 900°C.

ČSN 42 2952 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered stabilizing annealing (+SR).

Mechanical properties and values

1) On request of the customer and after agreement with the producer, it is possible to deliver the steel containing < 0.20% C. Thereby, the steel gains a higher resistance to corrosion. At the same time, the amounts of Re and HB are lowered slightly. This results in increasing in the values A, Z, K and K.

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 1150°C
  > max. 2 g S/m³ =< 1100°C
  < min. 2 g S/m³ unsuitable
• reducing + carburizing
  sulfur-free =< 1080°C
  > max. 2 g S/m³ =< 1040°C
  < min. 2 g S/m³ unsuitable

Yield point R_p 1 (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 60 N/mm²
• 800°C >= 36 N/mm²
• 900°C >= 18 N/mm²
• 1000°C >= 8 N/mm²

Weldability

Good. Preheating is not necessary with thicknesses up to 20 mm. Over 20 mm, the steel must be preheated to a minimum of 200°C. Cool in water after welding. New annealing is not needed after welding if the steel is to be used as heat resistant. In case ad 1), it is necessary annealing for the stress relieving.

Machinability

Good

Application

The steel is suitable for equipment, jigs, and tools for the ceramic and glass industries. For vessels for hardening salt baths with direct heating by submersion electrodes and with external heating of the vessels. For high strength and stressed transport equipment parts inside furnaces, etc.

ČSN 42 2955 (Cr-Ni steel)

Chemical composition in percents

The castings are delivered stabilizing annealing (+SR).

Mechanical properties and values

Maximum permissible heat load and resistance to sulphur products in atmospheres

• oxidizing + air
  sulfur-free =< 1170°C
  > max. 2 g S/m³ =< 1130°C
  < min. 2 g S/m³ unsuitable
• reducing + carburizing
  sulfur-free =< 1030°C
  > max. 2 g S/m³ =< 1050°C
  < min. 2 g S/m³ unsuitable

Yield point R_p (1 % elongation) in temperatures after 10 000 hours of static stress

• 700°C >= 58 N/mm²
• 800°C >= 34 N/mm²
• 900°C >= 19 N/mm²
• 1000°C >= 7 N/mm²
• 1100°C >= 2 N/mm²

Weldability

Good – up to 0.40% C content. Neither preheating or new annealing are necessary after welding.
Good to difficult when the steel contains more than 0.40% C. Preheating to 200°C is required. Weld with short interrupted weld beads and forge immediately. After welding is recommended a new annealing.

Machinability

Good

Application

For use in high temperature zones where the amount of heat varies, especially in oxidation atmospheres without the presence of sulphur and its combustion gas.
The steel is suitable for movable grates, beams, loading jigs for the glass furnaces, glass crucibles etc.
The steel is not susceptible to brittleness. It is not suitable for sulphur containing reduction atmospheres.