溶射皮膜をインサート材とした鋳鉄と炭素鋼の固相接合

フレーム溶射に関する研究(第4報)

抄録

The solid phase joining of ductile cast iron (FCD 600) and carbon steel (SS 400) was carried out using thermal spray coating of nickel based self-fluxing alloy under atmospheric conditions for basic data. The size of joining specimen is 50 mm in length and 10 mm in diameter. After the each edged surface of FCD600 and SS400 specimens were blasted by used steel grid material sized No. 100, those were sprayed with self-fluxing alloy (S.F.A.) at the each surface of both specimens coated about 100 μm in thickness.
The effects of joining conditions on the structure and strength of joints were studied. The joints with excellent metallographic structures were obtaind at the joining temperature near the melting point of the spray material.
The results are as follows :
(1) The maximum tensile strength at the joint part was more than 500 MPa under conditions of 50 sec raising time and 40 sec holding time at 1223 K temperature.
(2) The Vickers hardness distribution near the joining zone of FCD 600 was between Hv250 and Hv340. That was a little bit higher than base metal.
(3) The microstructure near the joining zone of FCD 600 did not indicate transformation to white pig iron because of its lower cooling rate. The structure around graphite was ferrite and the base metal was pearlite structure.
(4) By the EPMA line analysis across the joining zone of FCD 600, Cr, Ni and B were not observed because the inserted material S.F.A. was a very little diffused and the most of it was discharged out of the jointed part.