The Plant “Energosteel” starts manufacturing of steel grinding balls with diameter 30 mm
The representatives of OJSC "ArselorMittal" Krivoy Rog" have visited the Plant "Energosteel"
Manufacture
Technological scheme of balls production
The method of balls rolling on the hot rolling machines is one of the most contemporary and economical methods of production and has a number of significant advantages compared to casting and forging ones. Casting or forging of the balls are not very efficient (mainly manual manufacture), and are accompanied by significant loss of the metal (in the process of pouring, at the fin during forging). Transversal rolling of balls from the round billet is economical. It differs from other methods due to the possibility to produce grinding balls on the continuous automated aggregates, that allows 2-8 times to increase the output and reduce the consumption of metalby 10-15%.
1. Incoming control of billet. For the production of grinding balls the Plant “Energosteel” utilizes hot rolled round bar from carbonaceous and low alloyed steel, produced by leading Russian and Ukrainian metallurgical companies according to GOST 2540-88 «Hot-rolled steel round bar (assortment)» and GOST 1050-88 «Special calibrated iron specially conditioned on surface made of quality carbonaceous constractional steel: general technical conditions».
Before the industrial process the bill passes through the thorough control on conformity to the given geometrical parameters and chemical composition in an attested laboratory of metals of the Plant “Energosteel”.
2. Heating of billet. Heating is performed in modern inductive heating furnace, which ensures accurate temperature of rods at the outlet. Most ball manufacturers use gas furnaces which have a lot of significant shortcomings compared to inductive smelting furnace:
- they don’t give opportunity to heat bill evenly for the accurate rolling and necessary hardening because ofits large lifetime;
- in the process of billet heating in the gas furnace the cinder layer is formed on the surface. It leads to the steel decarbonization, and thus to the loss of balls surface hardness and strength;
- work of gas furnaces doesn’t envisage stops with a view to fix mills bucket and for other production needs, because it leads to a breach of internal lining. Absense of the breaking of thegas furnaces hampers the tuning of balls rolling complex and tempering in the production process;
- using of induction heating minimizes expenses on energy resources and reduces therisk of price increase due to changing state of gas market in Ukraine.
3. Rolling of grinding balls. After heating billet enters the inlet of screw gauges where it is rolled to balls.
4. Thermal treatment. Rolled balls come from screw gauges outlet to shelfs of the quenching drum through the inclined chute. After the quenching bath tempered balls come into package where self-tempering of the balls before loading takes place.
