HONDA Yoshioki Kurume College of Tech. ・Mat. Sci. & Met. Eng., Lecturer, 材料工学科, 講師 (10044281)
SHIGEMATU Kouki Kurume College of Tech. ・Mat. Sci. & Met. Eng. Asso. Prof., 材料工学科, 助教授 (20037964)
NAKAYAMA Masaru Kurume College of Tech. ・Mat. Sci. & Met. Eng., Professor, 材料工学科, 教授 (00044272)
SASAGURI Nobuya Kurume College of Tech. ・Mat. Sci. & Met. Eng., Asso. Prof., 材料工学科, 助教授 (50215737)
|Budget Amount *help
¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1989 : ¥2,300,000 (Direct Cost : ¥2,300,000)
The purpose of this research project is to develop the high temperature wem resistant materials with higher amount of carbides by means of melting process and by joining the two kinds of alloys.
Properties of the eutectic high Cr cast irons containing 10% to 40%Cr were investigated at the temperatures up to 1000 ﾟC using a torsion testing machine. Shear strain started to increase at 600 ﾟC and enlarged markedly in the temperature range from 800ﾟC to 1000ﾟC. High temperature strength, that is, shear stress disn't vary up to 600 ﾟC and it kept about the same strength as that at room temperature. Over 600 ﾟC, the strength decreased gradually as the temperature was increased, but even at 800ﾟC the strength was about 15OMPa. The 27%Cr cast iron was found to have most excellent strength at high temperatures.
Oxidation test at 1100 ﾟC was carried out under Po_2= 1 ate using 10%Cr eutectic cast iron separately added 10% of strong carbide forming element such as V, Mo, Nb and W. V greatly increas
ed the oxidation of the iron, and in other words it worsened the oxidation resistance. On the other hand, each element except V decreased the oxidation ratio and Nb improved oxidation resistance remarkably.
In order to reinforce the brittleness of high Cr cast iron with large amount of embides, 26%Cr eutectic iron, which has very high oxidation resistance and very superior high temperature properties, and mild steel were joined by means of brazing with pure. copper filler. When both alloys were held at the temperature range of 1100ﾟC to 1180ﾟC for enough time, they were well connected each other by alloyed phase(Fe-Cr-Cu-C)precipitated in molten copper and bond strength of the joint showed aliaest the same value as mother materials. This composite could be expected to use for wear resistant parts at high temperature.