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Stainless Steel Solution Nitriding at High Temperatures for Application in Mechanical and Chemical Engineering

Objective



Objectives and content

Stainless steels are very important materials for producing pumps and valves. Often typical applications are placed in the fields of water desalination plants, environmental technology or in chemical industries. An outstanding corrosion and hydroabrasive resistance as well as good tribological behaviour are required for some main pump components. Conventional stainless steels do not have sufficient properties due to complex loads in pump and valve applications.

It is the aim of this project to further develop and modify a completely new surface treatment process called "SOLUTION NITRIDING" and apply it to the components of pumps in order to increase their resistance to erosion and cavitation without any loss of corrosion resistance provided by the stainless steels of which they are made. The mechanical, chemical, tribological and combined properties of the solution nitrided surface zones have to be investigated under the severe conditions found in pumps for flue gas desulphurization, sea water desalination, etc.

The main objectives of the project are:

- development of stainless steels surface treatment with a N-content up to 0.8% in the case by a new diffusion process based method for high deepness - increase of surface hardness of >100% without reduction of corrosion resistance
- increase of erosion resistance of a factor of 10
- decrease of friction coefficient to values below 0.02
- improvement of selective corrosion by increase of PREN>40
The final result will be a high nitrogen surface treated, high corrosion and erosion resistant stainless steel for components for complex tribological, corrosive and abrasive application in sea water desalination plants, off-shore technology, chemical industries and biotechnology. After completion of the project a sufficient SOLUTION NITRIDING process due to time, temperature, size, cooling rate of different stainless steel components will be developed. The field tests and the verification of the obtained properties will be continued for about two years at least.

Claimed innovative aspects of the proposal include:

- Use of diffusion processing at solution temperature for stainless steels - Controlled heat treatment by calculations of material depending diffusion parameters
- Constitution of high nitrogen surfaces without formation of nitrides - Development of SOLUTION NITRIDING heat treatment process
The consortium comprises a manufacturer of pump and valves (KSB), the inventor of the basic process rules (UNI Bochum), a stainless steel producer (CENTRACERO), a producer of industrial heat treatment furnaces (IPSENABAR), a specialist in tribology investigations and an end-user of surface treatments (HEF), a research institute for corrosion and erosion examinations (DECHEMA) and an end-user of pumps and valves for water supplying and sewage processing (ANSA).

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Klein, Schanzlin & Becker AG (ZFS)
Address
9,Johann-klein-straße
67227 Frankenthal
Germany

Participants (6)

Aguas del Norte SA
Spain
Address
29-6,Avda. Lehendakari Aguirre
48014 Bilbao
Centracero SA
Spain
Address
De Estella
Murieta - Navarra
DECHEMA GESELLSCHAFT FUER CHEMISCHE TECHNIK UND BIOTECHNOLOGIE E.V.
Germany
Address
Theodor-heuss-allee 25
60486 Frankfurt Am-main
HYDROMÉCANIQUE ET FROTTEMENT R&D SA
France
Address
Zone Industrielle Sud, Rue Benoit Fourneyron
42166 Andrezieux-boutheon
Ipsen Abar UK Ltd
United Kingdom
Address
31 Dollman Street
B7 4RP Birmingham
Ruhr-Universität Bochum
Germany
Address
150,Universit¢tsstraãe 150
44780 Bochum