Study On Bimetallic Casting Technology Of High Chromium Cast Iron-alloy Steel

Metallurgical,power,mining,cement and other industries’ wear and tear consumption is enormous due to crushing,grinding and other processes.Especially hammer and other key components in the strong impact and wear conditions are prone to occur rapid wear,fracture and even failure.Wear parts manufactured by single material are becoming difficult to meet the requirements of harsh conditions.This article aims to study the key components of hammer crusher-hammer,carried out the optimization of bimetallic casting process,including the influence of process parameters,interface cleaning agent and mechanical vibration on the bonding performance of bimetallic composite casting interface,and made hammer crusher hammer applied in the actual assessment.The main findings are as follows:(1)Determine the casting process parameters: Pouring order for the first high-chromium cast iron(pouring temperature of 1460 ℃ ~ 1500 ℃),After pouring,immediately on its surface covered with a layer of borax additives(50wt.% Sodium tetraborate + 50 wt.% Graphite powder).After 3min interval,cast alloy steel metal(pouring temperature of 1580 ℃ ~ 1600 ℃).After the completion of pouring,immediately start the mechanical vibration(amplitude 2 cm,frequency 20 Hz),casting in mechanical vibration conditions to complete the crystallization,solidification.(2)Borax additive can reduce and remove the oxide on the metal surface,promoting alloy steel and high chromium cast iron fusion,improving the interface bonding strength,improving the quality of castings.The tensile strength of borax additive sample can be up to 530 MPa,and the tensile strength of the borax additive is 320 MPa due to the existence of oxide defects.(3)Mechanical vibration in the bimetallic casting process,is conducive to improving the organization and distribution of the organization,and refine the organization of grain.Among them,the bimetallic interface elements diffuse at 20 Hz vibration frequency,forming a wide stable interface binding region.The material composition and performance are smooth transition,and the comprehensive mechanical performance is the best.In the addition of borax at the same time using 20 Hz mechanical vibration casting,bimetallic specimen tensile strength of 629 MPa,room temperature impact power of 5.5 J/cm2.(4)The test results show that the service life of the high chromium cast iron-alloy steel bimetallic composite hammer head test shows that its service life is above 1600 h,and the service life of 450 h is higher than that of domestic similar products(high manganese steel).