New Welding Technology – saving technologies of welding and welding materials for construction metals and alloys

The specification statement of engineering problems and their solution:

Obtaining of qualitative welded joints at welding of articles of aluminium alloys hinders formation of defects (oxide inclusions, pores, poor joint welds reverse side formation, etc.) in joint welds because of activity and specific physical and chemical properties of aluminium and its alloys. Even at welding by the most reliable and widely spread in industry welding TIG, presence of defects in joints weld is observed, reducing mechanical and operating properties of welded joints, especially in basic structures and units. At the method of welding oxide film, promoting defects formation is removed only from the face of welding as the result of cathode sputtering effect with argon ions and from the reverse side oxide film remains and causes formation of faulty fusions, oxide inclusions and pores. Besides, because of great fluidity of aluminium at its welding a large number of burning-through is observed, as well as big joint weld root sagging, reducing resistance of welded joints to dynamic loads and its fatigue strength. The suggested technology is in special flux application (thickness of articles to 4 mm) at welding of aluminium and its alloys, applied as paste or flux tapes (thickness of articles to 10 mm), fixed on the welded edges from the reverse side. The fluxes and flux tapes application promotes defects removal, improvement of joint weld root formation and penetration protection against environmental effect, that increases mechanical and operating properties and characteristics of welded joints accordingly (Appendix 1). From the economic point of view the technology allows to reduce expenses on welding materials (wire and argon), operations on welded edges trimming before welding and quality control of welded joints.

At welding TIG of structural metals and alloys with more than 3 mm in thickness, for obtaining of qualitative welded joints it’s necessary to perform Y- or V-butt preparation of welded edges and perform welding in several passes that makes difficult the process of joints obtaining from both technical and economic points of view. Methods of welding with high-energy concentration (plasma welding and laser welding), allowing to perform welding of similar thicknesses for one pass, are not widely used in industry. Improvement of penetration ability of a welding arc at usual welding TIG proved to be possible at usual welding in the medium of activating fluxes, promoting increase of energy concentration in arc and allowing to perform welding of articles to 10 mm in thickness for one pass without welded edges preparation (Appendix 2). The method was known as A-TIG method of welding and patented by the Paton Welding Institute (Ukraine) for welding of steels and titanium, and for welding of aluminium and its alloys by the Tashkent Technical University (Uzbekistan). The list of flux for different metals and welding methods.

A development worker suggests new fluxes for the mentioned method of welding of aluminium and its alloys (Appendix 3), all types of steels (Appendix 4), titanium and its alloys and alloy on the nickel basis (Appendix 5). The use of the flux allows to increase efficiency of the welded structures and articles production by several times by removal of the operation of the welded edges preparation, reduction of a number of welding passes, electricity consumption as well as welding materials reduction.

Advantage compare with existing technologies:

The use of the suggested technologies conduces complete defects removal, discovered at control by non-destructive methods (radiography, ultrasound and electromagnetic methods also hermetically control). The mechanical properties welded joints, made with fluxes, are not lower than 0,9 of the basic metal properties and fracture of tested samples takes place by the basic metal or along the alloy line.

Rights on the intellectual property:

Three patents of the Republic of Uzbekistan were issued, one of them is patenting by PCT system. There are European and Australian patents. There are application on PCT system and an Inventor’s Certificate of the USSR on the methods of welding aluminium alloys with activating and scouring flux.

Competitive technologies:

Competing technologies of TIG welding of aluminium alloys and dealing with application of different engineering solutions (application of special liners, blowing with argon, etc.) don’t allow to eliminate all welding problems being solved at application of the suggested technology with flux application. The technology of welding A-TIG of aluminium and its alloys is unique in world practice. There are competitive fluxes for A-TIG method of welding of stainless steels suggested by Paton Welding Institute – “PATIG” (http://www.weldingtorch.co.uk/patign.html) and “FASTIG” (http://www.engineering.usu.edu/ite/Undergrad/Welding/Sr%20Posters/MikeMartinez/mikem.html) suggested by Edison Welding Institute (EWI). Comparative test has demonstrated that “PATIG” and “FASTIG” are less effective than “HC-10M” flux. For example, minimum weld energy for full penetration of 316L steel with thickness to 6,0 mm on “FASTIG SS-7” flux – 6,000 J/cm, on “PATIG” flux – 5,100 J/cm, and “HC-10M” flux 3,900 J/cm.

Economic efficiency:

The new proposed fluxes for fusion welding of aluminium and it’s alloys, all types of steel, titanium and it’s alloys, and also nickel based alloys in inert gas medium allow to increase productivity of weld constructions by minimising of joint weld, the weld passes numbers, electric energy and expenditure of welding materials. For example, the using of activated fluxes will allow to economise $15.6 and 65% time for aluminium alloys welding, $19.8 and 62% time for stainless steel welding, and $13.6 and 67% time for carbon and low-allow steel welding on 39.4 inch of joint weld.

Certification:

For the use of flux for welding of aluminium alloys in aircraft industry of the USSR Engineering manual TR 1.2.200-83 and operating instructions PI 1.4.1555-2000 (Russia) were issued. There are specifications TU Uz 64-15191715-002-98 of 25.08.98 for the flux application at A-TIG welding technique being in force on the territory of Uzbekistan. Besides, the French Agency issued quality certificates for the fluxes, i. e. welded joints, obtained at A-TIG welding (with a flux for aluminium Al-7- # 3NA98B003, with a flux for carbon steel # 3NA98B004 and with a flux for stainless steel # 3NA98B005). The quality certificates meet standards NF EN 288-4 edition 1993+A1 (for aluminium and its alloys) and NF EN 288-3 edition 1992+A1 (for steels) for high-pressure apparatus.

Industrial test and applying:

At present the TIG welding technology with the clearing flux use from the reverse side:

- has been in introduced at enterprises P/b M-5050 and P/b G-4184 (Moscow), Voronej Aircraft Industrial Amalgamation, Kazan Aircraft works, Saratov Aircraft works (Russia) and Tashkent Aircraft Industrial Amalgamation named after Chkalov V.P. (Uzbekistan) at welding of aircraft articles of the series IL, Yak and MIG;

- in 1990-1991 work on introduction of a new welding technology at Feodosiya Production Amalgamation “More” (Ukraine, Crimea) was performed for welding of casing structures of aluminium alloy 1561 of gas-turbine ships with hydrofoils “”Voskhod” and “Tsiklon”;

- from 1997 work is performed with Japanese firms “Toyota Motors Corporation” and “Sumitomo Corporation” on introduction of the technology of 5083 and 6061 aluminium alloys welding at “Toyota Motors Corporation” firm works.

Whereas the sollowing work is performed with application of the A-TIG welding technique:

- in collaboration with scientists of the laboratory of materials ISITEM of Nantes University and “C.D.S” firm representatives (tentative distributor in Europe) production tests of new fluxes for welding of steels, titanium and inkonel at the French enterprises “Aerospatical” (Sant-Nasaire), “Creusot Loire” (Cresot), “Polysoude” (Nantes) and “Leduc” (Nantes) have been performed;

- the flux of mark YC-27A for steel welding was introduced and taken for application by “Ulyanovsk-Eneroremont” enterprise (Ulyanovsk, Russia) for welding of articles and structures of carbon and low-alloy steels at assembly and repair of power units of heat and electric power stations;

- in Uzbekistan the flux of mark YÑ-27A is introduced by “Uzbekkhimmash” works (Chirchik city) for high pressure tanks welding.

Presentation of new productions at the International Exhibitions:

In October 1998 – presentation of new technologies and flux at the International Exhibition on Vehicles High-Pressure in Paris (France) together with the French “C.D.S.” corporation.

In April 1999 - presentation of new technologies and flux at the International Industrial Exhibition in Hanover (Germany) together with the French “Elitig” corporation.

In November 2000 - presentation of new technologies and flux at the International Industrial Exhibition “FABTECH-2000” (Cleveland, OHIO, USA) together with the American corporation “M.B. Industries Inn” (see photo).

In November 2001 - presentation of new technologies and flux at the International Industrial Exhibition “FABTECH-2001” (Chicago, IL, USA) together with the American corporation “M.B. Industries Inn”.

INTERNATIONAL INDUSTRIAL EXHIBITION “FABTECH-2000”

14-17 November 2000 (Cleveland, OHIO, USA)

Pictured at FABTECH-2000 are Dr. Rustam Saidov (center) of the Agency for Promotion of Research and Innovative Projects; Michael Borges (left), President of MB Industries, Inc.; and Ed Jackson (right), Sales Manager, MB Industries, Inc.