| 摘要 |
<p>#CMT# #/CMT# In a TIG bronze welding method for steel component(s) using a TIG welding torch, a fusible wire and a protective gas, the protective gas is a ternary gaseous mixture (I) containing (by volume) less than 5% helium (He), less than 1% hydrogen (H2) and argon (Ar) to 100%. #CMT#USE : #/CMT# The method is specifically used for bronze welding components of carbon steel or of galvanized or zinked carbon steel, especially in the production of automobile bodywork from carbon steel components, particularly using a welding torch carried by a robot arm (all claimed). #CMT#ADVANTAGE : #/CMT# High quality welds are obtained at high productivity rates. In particular use of (I) as inert gas has beneficial effects on welding speed (typically allowing speeds of 2-3.5 m per minutes with electro-zinked plates), wetting and the appearance of the weld region (specifically avoiding the porosity problems usually associated with copper-silicon (CuSi3) wires), cost (due to the low He content) and initiation. Various problems associated with use of other inert gases are eliminated, the arc instability associated with pure Ar, wetting deficiency associated with binary Ar-H2 mixtures, deformatiom problems associated with binary Ar-He mixtures and excessive energy consumption associated with ternary Ar-He-H2 mixtures having relatively high He and H2 contents. #CMT#METALLURGY : #/CMT# Preferred Process: (I) contains at least 0.1% (especially ca. 1%) He and 0.1-0.8% (especially ca. 0.5%) H2. #CMT#EXAMPLE : #/CMT# Uncoated or galvanized steel sheets (thickness 1 mm) were welded by TIG bronze welding using a copper-silicon (CuSi3) wire (diameter 0.1 mm), at a current of 170 A, a potential of 13 V, a welding speed of 2 ml per minutes and a wire speed of 5 ml per minute. Good results were obtained in both cases if welding was carried out under a mixture of (by volume) 1% helium (He), 0.5% hydrogen (H2) and argon (Ar) to 100%, whereas bad results were obtained in both cases under a mixture of 5% H2, 20% He and Ar to 100%.</p> |
