Steel is a material, which is very demanding in its way of production and which is really varied and adaptable in his future use.
Steel can be machined in different ways, the characters of the material are e.g.:
- good weld ability
- hard, tough and wear resistant
- resistant to corrosion and to heat
At foundry Reinhard Tweer GmbH the steel casting parts are produced in alloyed and non-alloyed qualities as well as heat treated (heat treated on air/and water) or non-heat treated.
SEW 520 High-strength cast steel with good weldability
SEW 685 Cold toughness cast steel
SEW 835 Cast steel for flame and induction hardening
DIN EN 10213 Cast steel for pressure vessels
DIN EN 10293 Cast steel for general applications
Spheroidal Cast Iron
Additional to the production of steel castings also spheroidal steel castings are produced at foundry Reinhard Tweer GmbH, in various qualities according to DIN EN 1563.
Spheroidal castings have a high strength and ductility because of the globular structure.
This material is used very often in vehicle industry.
Furthermore we produce bainitic cast iron (ADI) acc. DIN EN 1564.
These materials are produced on the basis of the normal spheroidal graphite casting melt by additional alloying elements and by a corresponding heat treatment. Thereby we achieve higher values regarding elongation, yield stress and tensile stress. These materials find a wide range of applications, e.g. in the automotive and engineering.
Using a modern simulation program and in coordination with the costumer, the geometry of the casting is already determined in advance in order to get the optimal casting. Afterwards, using this program, the feeder can be calculated and then there is an optimal use of the feeder. Because of this the output is optimal and the faulty casting is minimal.
The foundry Reinhard Tweer GmbH has its own pattern shop. There is the possibility to build the pattern in wood, resin or polystyrene. The pattern choice depends on the use; e.g. serial patterns are made of resin, single castings can be made of polystyrene.
The attention is put on special characteristics as e.g. shrinking allowance. The property of the shrinking allowance during the solidification process needs an allowance already during the patternmaking.
If the possibilities of the moulding plant are not sufficient, cores are needed.
At Reinhard Tweer GmbH there are five modern core shooting machines where cores are produced according the Cold Box-method. The hardening of the core sand is caused by the amino acid after addition of resin and hardener.
The core shooting machines are:
- 1 band automat company Klann (year of construction 2016)
- 1 core shooting machine Bicor (year of manufacture 2002)
- 1 core shooting machine Bicor (year of manufacture 2008)
- 2 core shooting machine Laempe (year of manufacture 2008)
Depending on the size of the casting and/or the batch size the castings are produced in the machine moulding shop or in the hand moulding shop.
The moulding shop comprises two semi-automatic moulding lines type Künkel-Wagner. The small moulding line, built in 1989 with a box size of 700x545x270/270 mm, has a capacity of 70-90 boxes per hour.
The big moulding line, built in 1991 with a box size of 1.100 x 1.100 x 270/270 mm, has a capacity of 30 boxes per hour.
On these moulding lines, castings with weights of 1 kg up to 400 kg can be produced. Here we use the Vacu-Airpress-Plus-method with bentonite moulding sand.
Small batches and bigger castings with a weight up to 5 t are formed in the hand moulding shop with cold resin setting.
Since 1996 the raw materials are melted in medium frequency induction furnaces.
Because of the batch system, a change of various materials is no problem. The raw materials are filled in the furnace with a charging launder.
The chemical analysis is determined with the help of a spectrographic analysis. The determined results are running automatically into the computer system in order to make certifications.
There are the following furnaces:
- 2 x 2,5 t: type ABB (built in 1996)
- 1 x 2,5 t: type ABB (built in 2005)
- 1 x 2,0 t: type ABB (built in 2000)
- 1 x 1,0 t: type ABB (built in 2000)
- 1 x 1,0 t: type ABB (built in 1991)
Cleaning and Annealing Shop
The cleaning shop has the required equipment, which is necessary for the further machining of the castings.
The heat treatment (tempering) of the parts can be carried out in a total of 11 electrically heated annealing furnaces.
The heat treating furnaces, electrically heated, have a capacity of up to 18 tons and meet all requirements on mechanical properties of steel and iron materials, because they enable an exact degree.
The temperature and time as well as the logging run completely by data processing.
For the pre- and after machining of the castings there are arc-air-cabines and further cleaning and welding equipment.
If castings have to be straightened, this can be done with the squeezing mechanism.
In collaboration with special suppliers we can offer the following machining processes:
For all our castings we can offer the machining. The scope of the machining is discussed with our customer before.
Coating and painting
Coating of the castings e.g. with oil, powder or lack can be done in the production process.