Date
05.02.2012 05:04:36

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Products

Our tubes and pipes can be divided into the following basic material classifications:


Corrosion resistant stainless steels
High temperature stainless steels

Corrosion resistant nickel based alloys
High temperature nickel based alloys

Grades of Stainless Steel

Corrosion resistant stainless steels

In our product programme we offer our customers two classes of stainless steels grades that have an excellent resistance to corrosion.Austenitic-ferritic stainless steels (duplex steels) are characterised by their excellent mechanical qualities, particularly their high stress corrosion cracking resistance. They are especially well-suited for maritime applications and in the chemical industry. Their excellent resistance to corrosion enables them to withstand a chloride medium, particularly under mechanical stress. This makes them superior to austenitic steels in many cases.The category of austenitic corrosion resistant stainless steels primarily includes materials with higher alloys (e.g. nickel, chrome and molybdenum). They are resistant to different types of corrosion caused by wet chemical influences, and are still able to maintain an austenitic face centred cubic matrix. This creates a range of highly versatile stainless steels.

High temperature stainless steels

High temperature stainless steels maintain their mechanical properties when exposed to elevated temperatures on either a short- or long-term basis.

Depending on the area of application these temperatures can rise e.g. to
- 500°C (932°F) in chemical processes
- 700°C (1,292°F) in power plant applications
- 1,000°C (1,832°F) for furnace engineering

With their increased concentration of chrome, silicon and aluminium they are especially resistant under the influence of hot gases as well as in salt and metal melting. However, the individual corrosion resistance is always dependent on the surrounding conditions, and can therefore not be precisely determined in a single testing.

Nickel based alloys

Corrosion resistant nickel based alloys

Nickel's high degree of corrosion resistance is due to the fact that it is a relatively noble metal within the galvanic electrochemical series of metals.
Adding chrome, molybdenum, copper and other elements to the alloys gives them an even higher resistance to oxidation and corrosion which makes it possible to use them in a wider range of applications. Seamless tubes and pipes made of corrosion resistant nickel alloys are the first choice for basic industry manufacturers due to their excellent resistance to various acids (sulphuric acid, hydrochloric acid, phosphoric acid) and alkaline solutions.

High temperature nickel based alloys

A further increase of specific alloy elements (such as chrome, molybdenum, tungsten, titanium, aluminium, niobium, etc.) improves the high temperature, high strength characteristics of austenitic steels. The disadvantage of austenitic stainless steels occurs in the fact that these elements have a reduced solubility. In order to compensate this effect and to reach the desired result, the nickel concentration can be increased. The highest alloyed types of high temperature nickel based alloys contain only a very low iron concentration.