Research Of Thin Slab Continues Casting And Rolling Low Alloy Wear Resistant Steel

The traditional hot rolled wear resistant steel plate often shows problems of serious surfacedecarburization, component segregation, uneven microstructure and high production costs. Thinslab continues casting and rolling process shows many advantages of slab cooling fast, small slabcomponent segregation, uniform fine billet grain size, homogeneous microstructure and fineprecipitate. The CSP (Compact Strip Production) process is a kind of thin slab casting and rollingprocess. In this paper,30CrMo,65Mn and50CrV4thin slab continue casting and rolling wearresistant steel were designed, the microstructure, mechanical properties and abrasion resistanceunder different heat treatment conditions are researched to provide references for thedevelopment, production and application of the thin slab casting and rolling wear resistant lowalloy steel.Results show that the microstructure of continue casting and rolling30CrMo steel consists offerrite and pearlite, microstructure of quenched30CrMo steel is made up of martensite andresidual austenitee, tempered martensite constitutes the microstructure of quenched and lowtemperature tempered30CrMo steel. The hardness, tensile strength, yield strength, impactabsorbed energy under-40℃and normal temperature of the3.4mm continue casting and rolling30CrMo steel are25.6HRC,1080MPa,1048MPa,18.2J and46.8J, respectively, comparedwith50.5HRC,1387MPa,1306MPa,63.2J and73.5J after quenching and low temperaturetempering. Besides, the hardness increases to52HRC after quenching; The hardness, tensilestrength, yield strength, impact absorbed energy under-40℃and normal temperature of the2.1mm continue casting and rolling30CrMo steel are27HRC,818MPa,595MPa,18J and50J,respectively, compared with50.2HRC,1365MPa,1276MPa,56J and72J after quenching andlow temperature tempering. Besides, the hardness increases to52.2HRC after quenching; Thehardness, impact absorbed energy under-40℃and normal temperature of the5mm continuecasting and rolling30CrMo steel are21.3HRC,20J and32.6J, respectively, compared with48.4HRC,22J and38J after quenching and low temperature tempering. Besides, the hardnessincreases to50HRC after quenching.The microstructure of continue casting and rolling50CrV4low alloy wear resistant steel consists of ferrite and pearlite, microstructure of quenched50CrV4steel is made up ofmartensite and a little undissolved ferrite, tempered martensite and undissolved ferrite constitutesthe microstructure of quenched and low temperature tempered50CrV4steel. The hardness,tensile strength, yield strength, impact absorbed energy under-40℃and normal temperature ofthe50CrV4continue casting and rolling low alloy wear resistant steel are21HRC,999MPa,918MPa,2.7J and9.1J, respectively, compared with51.8HRC,1599MPa,1480MPa,5.6Jand17.4J after quenching and low temperature tempering. Besides, the hardness increases to53HRC after quenching.The wear resistant of continue casting and rolling low alloy wear resistant steel is better thanthe hot rolled steel with the same chemical composition, the relative wear resistance of quenchedand tempered30CrMo,50CrV4steel specimens is more than1.6times Q235steel. The frictionalsurface of continue casting and rolling steel is relatively smooth with slight scratches. Themainly frictional surface of hot rolled45#,16Mn, Q235steel are furrow and cutting spalling, thefurrow becomes deeper and the cutting area increases.In conclusion, in the low stress abrasive wear conditions, continue casting and rolling30CrMo low alloy wear resistant steel shows the best overall performance taking themicrostructure, mechanical properties and wear resistant of the three kinds of continue castingand rolling low alloy wear resistant steels into account. The extreme low impact toughness limitsthe scope of application of50CrV4steel despite its excellent wear resistance and tensileproperties.