Microstructural and Compositional Changes of Binary Alloys by a Static Plasma Arc Local-Melting

概要

論文の詳細を見る
The microstructural change produced in discrete regions in Fe, Fe-C alloys and cast irons, the alloy element loss of a surface melted region in binary iron alloys and the decarburization of the melted region in Fe-C, Ni-C and Co-C alloys were moestigated under a static plasma arc. Cylindrical specimens were locally melted with a stationary plasma torch using argon plasma gas and Ar+H_2 shielding gas, and then, the interface microstructure of the plasma arc melted state and the chemical camp ost ion of the melted region were elucidated. In the melted region, the solidified structure changes from equiaxed to columnar crystal with the addition of carbon to Fe, and in east iron, columnar crystal cementite and ledeburite eatectic are recognized. In the fusion boundary region of Fe and Fe C alloy, epitaxial growth occurs on the fusion line, causing a great grain coarsening of the HAZ, and in cast iron, specific features such as line ledeburite, martensite and fine pearlite are exhibited. A loss of alloying element from the are-melted iron alloy region occurs by evaporation and the loss is considered to be rate-controlled by aiffusion in the gas boundary layer. The decarburization rate of the melted region increases with an increased hydrogen in the shielding gas.
社団法人溶接学会の論文
1985-04-01