Abstract
The specifications on the yield strength for standard malleable iron castings were given at the time when Japanese Industrial Standard was revised in 1969.
Thereby the authors have measured the yield strength of malleable iron castings produced in commercial foundries in the western area of Japan and have investigated various factors influencing the yield strength.
From results obtained, it is clarified that the yield strength of the castings producing in malleable iron foundries sufficiently satisfied the present specifications for standard malleable iron castings and also increasing silicon content of the castings raises the yield strength.
Moreover, the repeated reloading-unloading test on malleable iron was carried out to mearure permanent strain and elastic limit, and also to evaluate the yield strength from the stress-strain curve.
From the result obtained, it can be concluded that the value of yield strength is quite effective to indicate the practical value of mechanical strength of malleable iron castings.
