Study And Development Abrasion Resistant And Low Alloy Cast Steel Liner Of Large Ball Mill

ZG80CrMnSiMo Steel is a kind of new high carbon low alloy wear-resistantsteel used in large ball mill liner. In the paper, the temperature point of phase-transition of this wear-resistant steel was measured, quenching degree andhardenability of the steel were tested. Based on this, according to different designedquenching process and temper temperature, the test steel was heat-treated, combinedwith metallographic analysis, cast structure and post-heat-treatment structure of testmaterial were researched. The performance of material was evaluated by testinghardness, impact toughness, abrasive resistance and analysing topography of the wearsample. In the paper, according the size of actural liner, using ANSYS software, theliner temperature field’s changing patterns along with different cooling method,different hardening media and size of scale board were researched, The changingpatterns can provide reference for production practice.The test results are as follow: The transition curve of ZG80CrMnSiMo Steel’sover cooling austenite to pearlite and bainite move right. When cooling speed arebetween0.5℃/s and45℃/s, we can still get metallographic structure formed bymartensite and little retained austenite. Alloy steel go through high temperatureannealing, the main contains of the carbide are M3C、M7CandM23C6. Through1050℃×4h annealing, block carbides had disappeared, The grain size grade is about7class.This multicomponent alloy steel has good quenching degree and hardenability,quenching method (wind quenching, oil quenching and air quenching) doesn’t haveobvious effcet on micro-structure and performance, wind-cooling quenching can getmetallographic structure formed by martensite+residual austenite+carbide. Through870℃×2hwind quenching+500℃×2htemper, test steel’s microstructure are temperedmartensite+tempered troostite+carbide+residual austenite, hardness value is49HRC,impact toughness is33J/cm2, comprehensive mechanical properties are good, has good abrasive wear-resistance. Liner temperature field shows that: as quenching strongcooling media, water can avoid structure changing to pearlite and bainite. But retainedaustenite’s specific volume is higher than martensite, high cooling speed can lead toquenching flaw’s formation. The thickness of liner is a main factor which affect thecore and surface’s difference in temperature, if cooling time is not enough. Thick lineris long-time placed, because the heat of core liner spread to the surface of liner, evenmake the surface of liner temperature, affect the performance of casting.