The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple meas-urement of wear mass.The wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not clear.In this paper,a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn morphology.Results indicate that the boundary of carbide is preferred for corrosion because carbide presents a noblerVolta potential compared to the metal matrix or boundary region.Due to the oscillation of drive shaft between the claw surfaces of movable latch,the dominant wear mechanism on the upper surface ofclaw(USC)and lower surface ofclaw(LSC)is plastic deformation caused by impact wear.Mechanical impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of carbides.Corrosion promotes the broken carbides to fall off from the metal matrix.The generated fine carbides(abrasive particles)cause extra abrasive wear on USC when the movable brings the drive shaft upward or downward.As a result,USC has a higher wear volume than LSC.This research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.

Tianda Yu;Guozhong Fu;Yanqing Yu;Liting Zhu;Maofu Liu;Wei Li;Qiang Deng;Zhenbing Cai

The State Key Laboratory of Power Transmission Equipment&System Secu-rity and New Technology,Chongqing University,Chongqing 4000442,China;Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu 610041,China;Tribology Research Institute,SouthwestJiaotong University,Chengdu 610031,China;Sichuan Huadu Nuclear Equipment Manufacturing Co.,Ltd,Dujiangyan 611830,China

中国机械工程学报

[1]Tianda Yu;Guozhong Fu;Yanqing Yu;Liting Zhu;Maofu Liu;Wei Li;Qiang Deng;Zhenbing Cai-.Wear Characteristics of the Nuclear Control Rod Drive Mechanism(CRDM)Movable Latch Serviced in High Temperature Water)[J].中国机械工程学报,2022(02):111-120

Movable,Serviced,noblerVolta,ofclaw,latches

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