Study On The Preparation And Mechanical Properties Of Controlled Cooling Austem Pered Ductile Iron

Isothermal quenching nodular cast iron with excellent mechanical properties and high wear resistance,are widely used in various kinds of anti-wear work environment as wear parts.But the practice has proved that traditional isothermal quenching ADI technology production costs too much and the requirement of production line is much higher,and it is difficult to be achieved in the practical production.This paper is mainly on the basis of traditional ADI technology,combined with the characteristics of isothermal quenching,and giving fully consideration to the actual working condition requirement of wear-resisting cast ball mill in mine and put forward a new type of rapid cooling of the isothermal quenching process,so as to achieve the goal of lower production costs and increase productivity.The main content is as followed:First of all,through the finite element simulation software Deform-3D,simulate temperature field analysis for the quenching process of rapid cooling isothermal quenching process and the traditional ADI technology process.And analyze the difference between these two processse about cooling temperature.Then predict the time of quenching process and the thickness of martensitic surface layer by Deform-3 D.Secondly,in order to understand the differences in organization under the two kinds of processes,analyze the microstructure and morphology scan.Then analyze the influence on fast cooling isothermal quenching process organizationof austenitizing temperature and isothermal temperature these two kinds of heat treatment process parameters.Finally,through the hardness test,impact test and the wear experiment,analyze the influence on fast cooling isothermal quenching process mechanical properties of austenitizing temperature and isothermal temperature these two kinds of heat treatment process parameters,to make sure that the fast cooling isothermal quenching process can replaceTraditional ADI technology currently being applied on the ball-mill grinding-ball production in mine.Comprehensive analysis the experimental results,the following conclusions:For nodular cast iron,using the rapid cooling isothermal quenching can obtain austenite and acicular ferrite with good performance ADI wear-resisting cast balls.Its about 45 rockwell hardness HRC,equivalent to traditional ADI technology international standard high level of casting ball hardness.And its impact toughness aK value is greater than 10.It is significantly higher than the traditional ADI technology and some high chromium cast iron material that are widely used in mine which reducing the rate of fragile ball to the greatest degree.Its wear resistance is much close to the high chromium cast iron which has been widespread usesd.By changing the austenitizing temperature and isothermal temperatures can control ball casting base structure such as austenite,the content of acicular ferrite,acicular ferrite,and the purpose of the size and distribution of density.So that we can match the hardness and toughness of wear-resisting cast ball.Rapid cooling isothermal quenching method introduced in this study,compared with traditional ADI technology,each of them has advantages and disadvantages on performance.The wear-resisting cast balls producted by this method,which can meet requirements of the actual working condition,the most important thing is that this method is more economic for the point of production process.Because the traditional ADI process line must have a large enough salt baths.To say objectivly,the general factory is unable to produce standard ADI cast-ball,so we can use the rapid cooling isothermal quenching instead of the Austem pered ductile iron isothermal quenching process to produce wear-resisting cast ballsis,which are suitable for the different condition.