High Performance Steels with Corrosion Resistance
Low Alloyed Steels for Super-Deep Oil Wells and Metal Constructions for Natural Media of Southern Caucasus with Increased Corrosion Resistance and Mechanical Characteristics
Tech Area / Field
- MAT-ALL/High Performance Metals and Alloys/Materials
3 Approved without Funding
Institute of Metallurgy, Georgia, Tbilisi
- Oak Ridge National Laboratory, USA, TN, Oak Ridge\nCenter for Advanced Mineral & Metallurgical Processing, USA, MT, Butte
Due to its geographical location the climate of Georgia is unique: the main role in formation of the climate is formed by the Caucasus mountain range, influence of the black and Caspian seas defining existence in the region dry continental and medium wet climate and subtropical and tropical climate as well. Results of corrosion investigations in different regions of the South Caucasus can be used by the countries having the same climate (Japan, Korea, the USA and south Europe).
Nowadays grades of steals st. 45(0,45C); st.36Г2С(0,36CMn2Si) N80; APS10M4(0,13CMnSiCr2MoVAlTi); C90(0,35CMnM-oC-rNi); C95(0,45CMn2);X70000PSI for producing and transportation of oil in Russia, the USA, Europe and other countries are used.
Pipes made from them have low mechanical and corrosion resistance properties (service time no more than 0,5-1,5 years instead of normative 10 years) in the media of gas and oil producing wells, containing except oil and gas mineralized hydrogen sulfide water and sulfite reducing bacteria. For eliminating of these defects steel of grade 20XГ2РКаБа(0,2CMn2Cr with Ca and Ba) has been developed in the Institute of Metallurgy Academy of Sciences of Georgia, tubings made from it have been put to the test in oil fields of Georgia, Russia and Azerbaijan. It is established that stability of steel to honeycomb corrosion and sulfide cracking must be increased for its using in super-deep wells.
The aims of the project are: increasing of corrosion resistance of tubings and casing pipes for super-deep wells by the help of creation of special technology producing new law alloyed steel; getting sacrificial anodes (protectors) and multi component alloy for protecting metallized coating for main pipelines and metal constructions.
Mechanical properties and corrosion resistance of 0.2CMn2Cr based steel be raised by further adjustment of its composition, introduction of alloying elements after deep deoxidization and desulfate doping with micro additives, applying methods of ladle metallurgy. By means of thermal and high-temperature thermo mechanical treatment microstructures can be obtained, that will provide high mechanical properties and increased resistance to corrosion and sulfide cracking.
The same steels can be used for pipelines, metal constructions for marine pier pillars, gas and oil producing and oil refining equipment. For this, detailed investigations of corrosion properties of above-mentioned steels in complex aggressive media (seawater, atmosphere and soils) are required.
In order to protect metal constructions and oil-gas pipelines from corrosion it is proposed to develop Al-Zn based multi component alloy for metallized coatings and also to modify Mg-Al based protectors by introduction of more electronegative elements with the purpose of increasing their service life.
Kinetics and mechanism of corrosion of new steels and protective properties of protectors and alloys for coatings will be studied in natural environments: in oil producing wells, in seawater and atmosphere, in oil-gas route soils.
Tendency of steels to sulfide cracking, honeycomb corrosion, hydrogen permeability and hydrogen embrittlement will be examined. Studying of corrosion and electro-chemical characteristics of new steels and coatings under thin (50-350 micron) phase layers of electrolytes simulating various atmosphere are planned. The simulating apparatus has been created by authors of proposed project.
Mathematical modeling of corrosion evolution will be realized.
The structure of received materials will be studied by optical, electron microscopy and X-ray diffraction analyses. The mechanical properties will be investigated by micro hardness, yield and tensile strength, elongation, toughness, porosity and adhesion measurements.
The corrosion-electrochemical investigations will be carried on potentiometer, galvanometer and polarizing resistance measuring device, on the device measuring hydrogen permeability through steel membranes, by defining bending angle of hydrogenated samples at first crack appearance. The resistance to sulfide cracking will be estimated by standard TM.0177-90(NACE) method.
The realization of the project will allow to create technology of tubing and attached to them couplings for super-deep wells from new low alloyed high strength welding steel resistant to sulfide cracking and also to realize corrosion protection of mains and metal constructions by coating from new alloy on the basis of Zn-Al and protectors on the ground of Mg-Al.
The collective of the scientists participating in the project has long-term experience in creation of steels, alloys, metal and non-metal coatings successfully introduced into various industries. A large contribution has been brought in by them in standard methods of corrosion investigations and developing of protection methods from corrosion of the metal equipment in open-air conditions. The participants of the project were involved in a 25-year long COMECON program “Development of corrosion protection measurers”. Results of this program were applied on hydroelectric power station ERA-KKW-Nord (Germany) for protection of turbines against corrosion in sea water (with economic benefit only there was more than $3000000). Corrosion tests in above and underneath sea water media were carried out at corrosion stations of the Georgian Institute of Metallurgy in Batumi bay with its unique climate, which carries character both tropics and subtropics as well and in this aspect has no analogues. The developers of the project were the organizers and participants of the international conferences and symposiums. Their works have been published in many distinguished editions. The majority of them participated in weapon programs.
The realization of the project will enable the scientists of Georgia, including the weapon scientists to bring in the contribution in current main problems of materials science and corrosion will allow to create additional workplaces and assist conversion processes. As for foreign scholars and specialists they will be able to get acquainted and use new achievements of Georgian metallurgists in the field of creation of new materials with increased corrosion resistance and mechanical properties for oil and gas producing industry.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.