Research On Wear Resistance Of Martensitic Heat Resistant Steel With Different Hardness

The control rod driving mechanism(CRDM)is one of the critical moving components in the reactor body due to its structural reliability directly relates to reactor startup,power regulation,power maintenance,normal shutdown and safe shutdown under accident conditions.Roller and lead screw are the key transmission mechanical parts of the control rod driving mechanism,whose meshing transmission part bears abrasive wear loss.New high strength and high toughness martensitic stainless steels,1Cr16Ni4Mo2Cu2W1VN and 1Cr16Ni4CuMo2N,independently developed by the General Institute of steel research,were added to the material candidate selection of driving mechanism.At the same time,the research on the wear resistance between different materials of the driving mechanism needs to be further investigated in order to improve the overall life of the mechanismThe wear resistance of 95Cr18,1Cr16Ni4Mo2Cu2W1VN and 1Cr16Ni4Mo2N subjected to various heat treatments is systematically studied in this article.On the one hand,through the and other means to analyze the material.The properties and microstructural evolution of the quenched,cryogenic and tempered samples were carefully analyzed by the means of metallographic structure observation,mechanical property detection and scanning electron microscope(SEM),etc.On the other hand,the Amsler(MM200)friction and wear equipment and the HTMS measurement and control system were used to perform water-lubricated rolling tests and dry friction rolling tests on the circumferences of the three types of heat-treated samples.After the wear test,the surface morphology of worn samples was further characterized via body optical microscope,three-dimensional optical interference topography and scanning electron microscope(SEM)The results show that there are three main wear modes of the steel revealed by the rolling wear experiment,namely slight adhesion wear,abrasive wear and fatigue wear.The main wear forms under wet friction are adhesive wear and micro sliding,and the surface morphology is composed of material adhesion and furrow.The predominant wear form of dry friction wear is fatigue wear,which results in the surface morphology characterized by large areas of shedding and peeling as well as further increment of the wear depthThrough the study of the influencing factors of the hardness difference ranging from 2HRC to 6HRC on the wear resistance of the rolling friction pair of the 95Cr18 test steel,it is found that the active hardness does not change during the 120h test period.When the driven hardness is greater than the active one and gradually increases,the average friction coefficient of the friction pair decreases.Besides that,the smaller the weight loss of the friction pair,the lighter the surface wear.On the other hand,the investigation of the influence of the hardness difference ranging from 2HRC?9HRC on the wear resistance of the rolling friction pair of the tested steel for the roller and screw was also conducted.The results demonstrates that,during the 150h test period,the active hardness keeps stable and the average hardness coefficient of the friction pair is lower than the active hardness and progressively decreases.Moreover,the weight loss of the friction pair increases,and correspondingly the surface wear become serious.However,in the wet and dry wear environment,when the active hardness is unchanged,the increase in the driven hardness causes the reduction of overall wear of the friction pair.And the main as well as driven wear decreases simultaneously.Therefore,reasonable hardness matching benefits the wear resistance of friction pairs.