Shielding gas and arc-welding method

Abstract

The invention relates to a shielding gas for use in the arc welding of metallic work pieces. The invention further relates to a process for the arc welding of metallic work pieces using consumable electrodes, whereby a shielding gas stream is supplied to the work piece adjacent to the electrode. According to the invention, for shielding gases recommended for use in the MSG welding, preferably the MAG welding, of rust-proof steels, especially nickel-based materials, specialty steels, or high-alloy steels, a) if the shielding gas contains no helium, it contains carbon dioxide in a proportion of between 0.001% by volume and 1.9% by volume and b) if the shielding gas does contain helium, it contains carbon dioxide in a proportion of between 0.001% by volume and 0.9% by volume, in addition to argon, nitrogen, and, if applicable, helium.

What is claimed is:  
     
         1 . A shielding gas for use in the arc welding of metallic work pieces, comprising: 
 argon, nitrogen, between about 0.001% and about 0.9% by volume of carbon dioxide, and substantially no helium; or    argon, nitrogen, helium, and between about 0.001% and about 0.5% by volume of carbon dioxide.    
     
     
         2 . The shielding gas of  claim 1 , wherein the shielding gas comprises argon, nitrogen, between about 0.01% and about 0.5% by volume of carbon dioxide and substantially no helium; or argon, nitrogen, helium, and between about 0.01% and 0.45% by volume of carbon dioxide.  
     
     
         3 . The shielding gas of  claim 1 , wherein the shielding gas comprises argon, nitrogen, between about 0.001% and 0.9% by volume of carbon dioxide, and substantially no helium.  
     
     
         4 . The shielding gas of  claim 3 , wherein the shielding gas comprises argon, nitrogen, between about 0.01% and 0.8% by volume of carbon dioxide, and substantially no helium.  
     
     
         5 . The shielding gas of  claim 1 , wherein the shielding gas comprises between about 0.01% and about 0.5% by volume of carbon dioxide.  
     
     
         6 . The shielding gas of  claim 5 , wherein the shielding gas comprises between about 0.01% and about 0.45% by volume of carbon dioxide.  
     
     
         7 . The shielding gas of  claim 5 , wherein the shielding gas comprises between about 0.01% and about 0.1% by volume of carbon dioxide.  
     
     
         8 . The shielding gas of  claim 1 , wherein the shielding gas comprises between about 0.1% and about 20% by volume of nitrogen.  
     
     
         9 . The shielding gas of  claim 8 , wherein the shielding gas comprises between about 0.5% and about 15% by volume of nitrogen.  
     
     
         10 . The shielding gas of  claim 8 , wherein the shielding gas comprises between about 1% and about 10% by volume of nitrogen.  
     
     
         11 . The shielding gas of  claim 8 , wherein the shielding gas comprises between about 2.5% and about 7.5% by volume of nitrogen.  
     
     
         12 . The shielding gas of  claim 1 , wherein the shielding gas comprises about 70% or less by volume of helium.  
     
     
         13 . The shielding gas of  claim 1 , wherein the shielding gas comprises between about 1% and about 50% by volume of helium.  
     
     
         14 . The shielding gas of  claim 13 , wherein the shielding gas comprises between about 2% and about 30% by volume of helium.  
     
     
         15 . The shielding gas of  claim 13 , wherein the shielding gas comprises between about 3% and about 20% by volume of helium.  
     
     
         16 . The shielding gas of  claim 13 , wherein the shielding gas comprises between about 5% and about 10% by volume of helium.  
     
     
         17 . A shielding gas for use in the arc welding metallic work pieces, consisting essentially of: 
 argon, nitrogen, and between about 0.001% and about 0.9% by volume of carbon dioxide; or    argon, nitrogen, helium, and between about 0.001% and about 0.5% by volume of carbon dioxide.    
     
     
         18 . The shielding gas of  claim 17 , wherein the shielding gas is composed of between about 0.1% and about 20% by volume of nitrogen.  
     
     
         19 . The shielding gas of  claim 17 , wherein the shielding gas is composed of about 70% or less by volume of helium.  
     
     
         20 . In a method for arc welding of metallic work pieces using consumable electrodes, the improvement comprising: 
 Supplying a shielding gas stream to a work piece adjacent to an electrode, wherein the shielding gas comprises argon, nitrogen, between about 0.001% and about 0.9% by volume of carbon dioxide, and substantially no helium; or argon, nitrogen, helium, and between about 0.001% and about 0.5% by volume of carbon dioxide.    
     
     
         21 . The method of  claim 20 , wherein the method of arc welding is MSG welding.  
     
     
         22 . The method of  claim 20 , wherein the method of arc welding is MAG welding.  
     
     
         23 . The method of  claim 20 , wherein the work piece is composed of a rust-proof steel.  
     
     
         24 . The method of  claim 23 , wherein the work piece is composed of a material selected from the group consisting of nickel-based materials, specialty steels, and high-alloy steels.  
     
     
         25 . The method of  claim 20 , wherein the shielding gas comprises argon, nitrogen, between about 0.01% and about 0.5% by volume of carbon dioxide and substantially no helium; or the shielding gas comprises argon, nitrogen, helium, and between about 0.01% and 0.45% by volume of carbon dioxide.  
     
     
         26 . The method of  claim 20 , wherein the shielding gas comprises argon, nitrogen, between about 0.001% and 0.9% by volume of carbon dioxide, and substantially no helium.  
     
     
         27 . The method of  claim 26 , wherein the shielding gas comprises argon, nitrogen, between about 0.01% and 0.8% by volume of carbon dioxide, and substantially no helium.  
     
     
         28 . The method of  claim 20 , wherein the shielding gas comprises between about 0.01% and about 0.5% by volume of carbon dioxide.  
     
     
         29 . The method of  claim 28 , wherein the shielding gas comprises between about 0.01% and about 0.45% by volume of carbon dioxide.  
     
     
         30 . The method of  claim 28 , wherein the shielding gas comprises between about 0.01% and about 0.1% by volume of carbon dioxide.  
     
     
         31 . The method of  claim 20 , wherein the shielding gas comprises between about 0.1% and about 20% by volume of nitrogen.  
     
     
         32 . The method of  claim 31 , wherein the shielding gas comprises between about 0.5% and about 15% by volume of nitrogen.  
     
     
         33 . The method of  claim 31 , wherein the shielding gas comprises between about 1% and about 10% by volume of nitrogen.  
     
     
         34 . The method of  claim 31 , wherein the shielding gas comprises between about 2.5% and about 7.5% by volume of nitrogen.  
     
     
         35 . The method of  claim 20 , wherein the shielding gas comprises about 70% or less by volume of helium.  
     
     
         36 . The method of  claim 20 , wherein the shielding gas comprises between about 1% and about 50% by volume of helium.  
     
     
         37 . The method of  claim 36 , wherein the shielding gas comprises between about 2% and about 30% by volume of helium.  
     
     
         38 . The method of  claim 36 , wherein the shielding gas comprises between about 3% and about 20% by volume of helium.  
     
     
         39 . The method of  claim 36 , wherein the shielding gas comprises between about 5% and about 10% by volume of helium.