Castings of steel 110G13L produced by many plants have coarse austenite grains (from -1 to + 1 points in accordance with GOST 5639-82) which are not regulated and not controlled. However, it has been shown that ladles of mining machines, drags in particular, have a diminished operating stability. The present paper is devoted to the effect of grain size on the mechanical properties, the intensity of strain hardening, and the abrasion strength under impact loading of manganese austenite steel 1 I OGI3L.The special features of the formation of grain structure in steel tl0GI3L have been studied in [1][2][3][4], where recommendations have been developed on a heat treatment technology of castings that ensures grain disintegration. However, in most cases these recommendations are not observed in practice. Numerous recent studies of manganese austenite steels have shown that distortions of the crystal lattice and near-order structures [5 -8] have a strong effect on the properties of steels. Novel metastable austenite steels with a diminished content of carbon and manganese and an additional amount of chromium have been suggested, which possess an elevated abrasion strength due to the development of a reverse martensite transformation caused by straining in the course of operation [9][10][11]. Steels with a diminished content of manganese are of special interest but have the disadvantage of low impact toughness, which can only be increased by diminishing the grain size.We studied 2 steel 110G13L (1.28% C, 12.2% Mn, 0.77% Si, 0.050% P, 0.008% S) after quenching in water from the austenization temperature, yielding an austenite structure without carbide segregations. In order to ensure a grain size corresponding to No. 5, the preforms of specimens were preliminarily subjected to a hold at the temperature of austenite destabilization, so that the "/-phase transformed into a mixture of an or-phase and carbides, and then to austenization at 1050~ and cooling in water. Austenite grain sizes Nos. 1 -4 were obtained after heating the metal to 1300, 1250, 1150, and 1100~ with subsequent quenching in water.Specimens 10 mm in diameter with design length l = 5d were tested for tensile strength; Menage specimens were used for determining the impact toughness a I . Plotting the de- pendences of %, 5, and a I on the grain size we established that these curves behaved virtually similarly though they did not coincide. We superimposed the dependences of %, 8, and a I on the grain size so that the points of their beginnings (grain size No. 1) and ends (No. 5) coincided. Then we changed the scales of the plots with respect to the relative elongation and the impact toughness. Under these conditions the dependences of %, 5, and a I on the grain size coincided almost completely, which means that all these characteristics can be represented by one curve, given that the coordinate axes are shifted appropriately (Fig.
