| 摘要 |
PURPOSE: To provide an alkaline glass for welding materials which is capable of uniformly supplying a flux at the time of welding, capable of preventing weld defects, such as pit, blowholes and low-temp. crack by stably generating arcs in a low-temp. current area as well and has excellent moisture absorption resistance. CONSTITUTION: This alkaline glass for welding materials contains 60.0 to 84.0wt.% SiO2 , 5.0 to 10.0wt.% Na2 O, 2.0 to 4.0wt.% K2 O and 5.0 to 15.0wt.& B2 O3 . A sample 4 is put into an alumina crucible 3 and is heated in a heating furnace 2. The expansion and contraction of this sample 4 are detected by a quartz rod 1 on which 5g load is acted. The temp. of a firing treatment is determined by the softening point detected by this quartz rod. The firing treatment is executed by this temp. and the grain size and specific surface area are adjusted.
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