1993 年 11 巻 4 号 p. 474-478
Cast iron is one of difficult material to weld. After welding of cast iron material, the heat-affected zone has higher hardness, martensite structure and high cracking susceptibility for high carbon contents.
The base metal used in this study was the nodular graphite cast iron bar (JIS type FCD 600) and the material of the thermal spray was the self-fluxine alloy (S.F.A.).
In this paper, the principal objective of the experimental study was to obtain the basic data for investigation of the mechanical and metallurgical properties.
The experimental findings may be summarized as follows :
(1) The maximum tensile strength reached about 480 MPa of which is about 80% of the tensile strength of the base metal.
(2) The Vickers hardness distribution near the heat-affected zone was about Hv400.
(3) The micro structure near the heat-affected zone does not indicate transformation to white pig iron because of lower cooling rate. The structure around graphite is ferrite.
(4) The tensile fracture surface shows a dimple fracture pattern at 1223 K peak temperature.