| 摘要 |
The invention relates to metallurgy, in particular, to production of thermal-strengthened steel balls, used for crushing of materials. A method comprises the rolling of balls at temperature 950-1000 °C, subcooling on killed air during of 35-190 s and quenching of water duration of 30-140 s, after that self-tempering is subjected in closed reservoirs duration of 24-50 hours. The balls are produced of steel having the following chemical composition, w/w: C – 0.6-1.2; Mn – 0.31-1.04; Cr – no more than 0.75; Si – 0.18-0.50; Al – 0.01-0.05; Fe – the rest. The minimal total contents of manganese and chromium in steel is established from the ratio: [% Mn]+0.56-[% Cr]=0.003-d+0.68, wear [% Mn] and [% Cr] – contents of manganese and chromium in steel correspondingly, w/w:d– diameter of ball, mm. Technical result: achievement of levels of hardenability and quenching, necessary for producing of balls of diameters from 40 to 120 mm of the 4-th group of hardness according ДCTУ 3499. |
