Heat Treatments Effect On Microstructureand Mechnical Property Of Carbide Particles Reinforcedalloy Steel

Mine cutter is the common unit installed in coal miner for crush coal. It is hugeconsumption by abrasion and large impact loads for direct contacts with the coal and sand.Most normal steel are difficult to meet the needs of high wear resistance and toughnessused as cutter materials. The particle reinforced steel matrix composites are very usefulfor combination the properties of hard phase particles and steel substrate. The steel of40CrNi2Mo is chosen as substrate. There are some properties of high Rockwell hardnessand toughness after quench and tempering with high temperature of40CrNi2Mo, it ishard to form shear zone under the high-speed shock, which shows good mechanicalproperty. The composite is cast by40CrNi2Mo and WC which shows the properties ofhigh hardness and wear resistance, mean well the good wettablity with steel substrate forthe prepare of cutter. Observation and analysis the microstructures and the distribution ofWCp after different heat treatments by various detection methods. Then test the abrasionperformance and other mechanical properties of composites added different WCpcontents, which contrast with the picks.It was shown that there are much pearlite, some cementite and little segregation in thecomposite of WCp/40CrNi2Mo in cast state, the W element is distributed uniform. Withthe content increase of WCp, the diameter of microstructure become smaller. Thesegregation is eliminated by quench and tampering. Carbide particles distribute uniformlybetween short lath ferrite. The hardness reduces with the temperature increase of tempering.The composites with2%(wt%) and5%(wt%) WCp can get the hardness of HRC51andHRC47after tempering at180℃for2hrs plus air cooling. The hardness of composite withWCp8%(wt%) is HRC43after tempering at220℃, and the hardness decrease aftertempering at higher or lower temperature. The wearable property is not determined byhardness. The wearable property is best of the composite with WCp8%(wt%)aftertempering at220℃, which is37.3%and14.7%than the wearable property of the two cutpick materials chosed for contrast.Key words: heat treatment, matrix composites, microstructure, wear resistance...