the invention will now be explained in greater detail with reference to embodiments thereof . flux - cored wires ( a , b and c ) 1 . 6 mm in dia having a core formed from the proposed flux composition were used for welding steel test pieces . steel sheath of each wire constituted 83 % by weight of the flux - cored wire and contained the following ingredients , by weight percent : carbon - 0 . 05 ; manganese - 0 . 020 ; silicon - traces ; sulphur - 0 . 010 ; phosphorus - 0 . 010 . welding steel test pieces was effected in a vertical position with a semiautomatic process using d . c . current of reversed polarity of 200 amp , and welding arc voltage of 23 v . carbon dioxide ( co 2 ) was used as a shielding gas . the steel in the test pieces 20 mm thick contained 0 . 18 % of carbon , 0 . 45 % of manganese , 0 . 20 % of silicon , 0 . 020 % of sulphur , 0 . 015 % of phosphorus , and the balance - iron . the flux composition used as a core in the flux - cored wire is given in table 1 below . table 1______________________________________ flux - cored wire a b ccore ingredients weight percentage of the ingredients______________________________________rutile concentrate 20 . 0 33 . 2 46 . 5ferromanganese 10 . 0 12 . 5 15 . 0ferrosilicon 1 . 30 2 . 0 2 . 60sodium fluosilicate 1 . 0 2 . 1 3 . 3calcined magnesite 1 . 3 5 . 6 10 . 0electrocorundum 1 . 6 4 . 1 6 . 7iron powder 64 . 0 40 . 5 15 . 9______________________________________ metal of the weld produced with the use of the flux - cored wires having a core formed from the above flux composition was tested for notch impact strength , specific elongation , and tensile strength , and were subjected to chemical and physical analysis for determining gas content ( oxygen , nitrogen and hydrogen in the weld metal . oxygen , nitrogen and residual hydrogen content in the weld metal was found by using conventional methods of vacuum melting , whereas the content of diffusive hydrogen was determined by the international standard iso 3690 . the comparative results of mechanical tests and chemical analysis given in tables 2 and 3 illustrate the advantages of the flux - cored wires having a core formed from the proposed flux over the prior art flux - cored wire ( u . s . pat . no . 3 , 800 , 120 ). table 2______________________________________tested notch impact strengthflux - tensile ( charpy v - notch test ) cored strength elonga - kgm / cm . sup . 2wire kg / mm . sup . 2 tion in % + 20 ° c . - 20 ° c . - 40 ° c . ______________________________________a 50 . 5 29 . 5 11 . 5 - 5 . 2 - 5 . 8 3 . 5 - 4 . 2 12 . 5b 55 . 0 30 . 2 14 . 0 - 6 . 4 - 11 . 7 5 . 7 - 8 . 5 17 . 7c 60 . 4 22 . 5 10 . 1 - 3 . 8 - 4 . 2 3 . 5 - 3 . 7 11 . 3prior art ( u . s . pat . no . 3 , 800 , 120 ) 65 . 0 20 . 5 7 . 5 - 2 . 5 - 3 . 0 0 . 8 - 0 . 8 9 . 0______________________________________ table 3______________________________________ total content of residual and diffusive hydro - gen , cm . sup . 3 pertested flux - gas content , weight % 100 gcored wire oxygen nitrogen hydrogen______________________________________a 0 . 058 0 . 012 5 . 5b 0 . 036 0 . 008 3 . 5c 0 . 044 0 . 007 4 . 0prior art ( u . s . pat . no . 3 , 800 , 120 ) 0 . 09 0 . 016 12 . 0______________________________________ as can be seen from table 2 the weld metal resulting from welding with the use of flux - cored wires a , b and c , features better mechanical properties then the weld metal obtained by using a flux - cored wire formed according to u . s . pat . no . 3 , 800 , 120 . in addition , the efficiency of the welding process in the case of the said flux - core wires is about from 2 . 4 to 3 . 8 kg per hour , which is 1 . 5 - 2 times higher than that obtained by using a flux - cored wire formed according to the above u . s . patent . flux - cored wires having cores formed from the flux of the invention provides for a proper formation of the weld metal and easy removal of the slag coat , as well as high resistance to hot cracks , and a low content of gases . flux - cored wires ( a , b and c ) of 2 . 2 mm in dia having a core formed from the proposed flux composition were used for welding steel test pieces . steel sheath of each wire constituted 80 % by weight of the flux - cored wire and contained the following ingredients , by weight percent : welding steel test pieces was effected in a vertical position ( horizontal weld on a vertical surface ) with a semiautomatic process using d . c . current of reversed polarity of 350 amp and welding arc voltage of 27 v . carbon dioxide ( co 2 ) was used as a shielding gas . the steel in the test pieces 20 mm thick contained 0 . 18 % of carbon , 0 . 45 % of manganese , 0 . 20 % of silicon , 0 . 020 % of sulphur , 0 . 0 . 015 % of phosphorous , and the balance - iron . the flux composition used as a core in the flux - cored wire is given in table 1 below . table 1______________________________________ flux - cored wire a b ccore ingredients weight percentage of the ingredients 1 2 3 4______________________________________rutile concentrate 30 . 0 38 . 5 47 . 0ferromanganese 17 . 5 20 . 0 22 . 5ferrosilicon 2 . 0 4 . 0 6 . 0sodium fluosilicate 1 . 5 3 . 2 5 . 0calcined magnesite 2 . 0 6 . 0 10 . 0electrocorundum 2 . 5 5 . 0 7 . 5iron powder 44 . 5 23 . 3 2 . 0______________________________________ metal of the weld produced with the use of the flux - cored wire having a core formed from the flux of the invention was tested for notch impact strength , specific elongation , and tensile strength , as well as analized for gas content ( oxygen , nitrogen and hydrogen ) in the weld metal . oxygen , nitrogen and residual hydrogen content in the weld metal was found by using conventional methods of vacuum melting , whereas the content of diffusive hydrogen was determined by the international standard iso 3690 . table 2______________________________________testedflux - tensile elonga - notch impact strength ( charpycored strength , tion , v - notch test ) kgm / cm . sup . 2wire kg / mm . sup . 2 in % + 20 ° c . - 20 ° c . - 40 ° c . 1 2 3 4 5 6______________________________________a 53 . 2 28 . 5 10 . 5 - 11 . 2 4 . 5 - 5 . 3 2 . 0 - 3 . 5b 57 . 0 29 . 2 12 . 5 - 13 . 8 6 . 5 - 7 . 0 3 . 5 - 4 . 0c 62 . 0 24 . 5 9 . 8 - 10 . 2 4 . 2 - 5 . 0 1 . 8 - 3 . 0______________________________________ the comparative results of mechanical tests and chemical analysis given in table 3 illustrate the advantages of the flux - cored wires having a core formed of the proposed flux over the prior art flux - cored wire ( u . s . pat . no . 3 , 800 , 120 ). table 3______________________________________ total content of residual and diffusive hydro - tested flux - gas content , weight % gen , cm . sup . 3 per 100 gcored wire oxygen nitrogen hydrogen______________________________________a 0 . 055 0 . 011 4 . 6b 0 . 040 0 . 010 3 . 8c 0 . 044 0 . 011 5 . 2prior art ( u . s . pat . no . 3 , 800 , 120 ) 0 . 09 0 . 016 12______________________________________ as can be seen from tables 2 and 3 the weld metal resulting from welding with the use of flux - cored wires a , b and c features a high mechanical properties . the flux - cored wires having cores formed from the flux of the invention provides for a proper formation of the weld metal and easy removal of the slag coat , as well as high resistance to hot cracks , and a low content of gases . in addition , the efficiency of the welding process in the case of the said flux - cored wires is up to 8 kg per hour which is 1 . 5 times higher than that obtained by using a flux - cored wire manufactured according to u . s . pat . no . 3 , 800 , 120 . flux - cored wires ( a , b and c ) of 2 . 5 mm in dia having a core formed from the proposed flux composition were used for welding steel test pieces . steel sheath of each wire constituted 70 % by weight thereof and contained the following ingredients , by weight percent : carbon - 0 . 08 ; manganese - 0 . 30 ; silicon - 0 . 12 ; sulphur - 0 . 030 ; phosphorus - 0 . 030 . welding steel test pieces was effected in a vertical position with a semiautomatic process using d . c . current of reversed polarity of 450 amp and welding arc voltage of 32 v . carbon dioxide ( co 2 ) was used as a shielding gas . the steel in the test pieces 20 mm thick contained 0 . 18 % of carbon , 0 . 45 % of manganese , 0 . 20 % of silicon , 0 . 020 % of sulphur , 0 . 015 % of phosphorus , and the balance - iron . the flux composition used as a core in the flux - cored wire is given table 1 below . table 1______________________________________ flux - cored wire a b ccore ingredients weight percentage of the ingredients 1 2 3 4______________________________________rutile concentrate 20 . 0 33 . 2 46 . 5ferromanganese 10 . 0 12 . 5 15 . 0ferrosilicon 1 . 30 2 . 0 2 . 60sodium fluosilicate 1 . 0 2 . 1 3 . 3calcined magnesite 1 . 3 5 . 6 10 . 0electro corundum 1 . 5 4 . 1 6 . 7iron powder 64 . 8 40 . 5 15 . 9______________________________________ metal of the welds produced with the use of the flux - cored wires ( a , b and c ) was tested for notch impact strength , elongation , and tensile strength , as well as analized for gas content ( oxygen , hydrogen and nitrogen ) in the weld metal . oxygen , nitrogen and residual content in the weld metal was found by using conventional methods of vacuum melting , whereas the content of diffusive hydrogen was determined by the international standard iso 3690 . table 2______________________________________testedflux - tensile notch impact strength ( charpycored strength elonga - v - notch test ) kgm / cm . sup . 2wire kg / mm . sup . 2 tion in % + 20 ° c . - 20 ° c . - 40 ° c . 1 2 3 4 5 6______________________________________a 50 . 2 29 . 5 12 . 1 - 12 . 4 4 . 5 - 4 . 8 3 . 0 - 4 . 2b 54 . 3 29 . 8 13 . 5 - 14 . 1 6 . 5 - 7 . 1 3 . 5 - 4 . 5c 60 . 0 23 . 0 10 . 5 - 11 . 1 4 . 0 - 4 . 3 2 . 8 - 4 . 4______________________________________ table 3______________________________________ total content of residual and diffusive hydro - tested flux - gas content weight % gen , cm . sup . 3 per 100gcored wire oxygen nitrogen hydrogen______________________________________a 0 . 050 0 . 010 5 . 0b 0 . 034 0 . 008 3 . 6c 0 . 041 0 . 012 4 . 1prior art ( u . s . pat . no . 3 , 800 , 120 ) 0 . 09 0 . 016 12______________________________________ as can be seen from table 2 the weld metal resulting from welding with the use of flux - cored wires of the invention features a high mechanical properties . these flux - cored wires provide for a proper formation of the weld metal and easy removal of the slag coat , as well as high resistance to hot cracks and low content of gases . the efficiency of the welding process with the use of the proposed flux - cored wires is up to 15 kg per hour . rate of formation of angular weld joint , depending on cathetus thereof , constitutes 50 - 80 m per hour . welding test pieces was carried out in the same way , as in example 1 , with the flux - cored wires having a core wherein the ingredients were taken in amounts lower than those indicated in the claimes . the flux - cored wire used was 1 . 6 mm in diameter , and the steel sheath thereof contained the following ingredients , by weight percent : carbon - 0 . 06 ; manganese - 0 . 23 ; silicon - 0 . 09 ; sulphur - 0 . 020 ; phosphorus - 0 . 020 . welding was effected with a welding current of 450 amp , and welding arc voltage of 36 v . the flux was composed of the following ingredients , by weight percent : ______________________________________rutile concentrate 19 . 5ferromanganese 9 . 8ferrosilicon 1 . 0sodium fluosilicate 0 . 8calcined magnesite 1 . 2electrocorundum 1 . 4iron powder balancebelow arc given mechanical test results : tensile strength , kg / mm . sup . 2 47 . 0specific elongation , % 24 . 0impact strength ( charpy v - notch test ), kgm / cm . sup . 2 :+ 20 ° c . 7 . 2 - 7 . 5 - 20 ° c . 2 . 0 - 2 . 3 - 40 ° c . 1 . 2 - 1 . 5______________________________________ as can be seen from the above mechanical test results the weld metal features lower mechanical properties : there ware observed more pores and crocks , as well as lower arcing stability and more intensive spattering of the electrode metal . welding test pieces was effected , generally , as in example 3 , with the flux - cored wires having a core wherein the ingredients were present in amounts exceeding the upper limits indicated in the attached claims . the flux - cored wire used was 2 . 5 mm in diameter , and the steel sheath thereof constituted 70 % of weight of the wire and contained the following ingredients , by weight percent : carbon - 0 . 08 ; manganese - 0 . 30 ; silicon - 0 . 12 ; sulphur - 0 . 030 ; phosphorus - 0 . 030 . welding test pieces was done with welding current of 450 amp and welding arc voltage of 32 v . the flux was composed of the following ingredients , by weight percent : ______________________________________tensile strength , kg / mm . sup . 2 64specific elongation , % 19 . 5impact strength ( charpy v - notchtest ), kgm / cm . sup . 2 :+ 20 ° c . 8 . 0 - 9 . 2 - 20 ° c . 1 . 7 - 2 . 0 - 40 ° c . 1 . 1 - 1 . 3______________________________________ as can be inferred from the above test results , the use of the flux having ingredients taken in amounts exceeding the upper limits indicated in the attached claims results in lower welding properties of the said welding wire . in addition , there takes place more intensive spattering of the electrode metal . it also affect the formation process of the weld and lowers the weld metal plasticity . while particular embodiments of the invention have been shown and described , various modifications thereof will be apparent to those skilled in the art and therefore it is not intended that the invention be limited to the disclosed embodiments or to the details thereof and the departures may be made therefrom within the spirit and scope of the ivention as defined in the claims .