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 SchemeCSC - Cost-sharing contracts
Murieta - Navarra
60486 Frankfurt Am-main
B7 4RP Birmingham