Research And Application On The Efficient Processing Technology Of High-pressure Outer Casing In The Nuclear Power

The CPR1000project of Shanghai Turbine Plant has been improved asecond-generation nuclear power technology program after the introduction ofimprovements and innovation,and it is formed with advanced, mature, goodeconomy. The unit’s high-pressure outer casing, due to its bulky, complex shapeand high precision,is very difficult to machining. Especially the horizontalequatorial surface of the casing is covered with a Inconel182alloy,and themachining quality and efficiency were always not good.Firstly, this paper evaluated the cutting performance of Inconel182alloymaterials,and then designed some cutting tests,through which the cuttingforce,surface quality, chip breaking performance, microstructure and tool life werecompared.After those tests, the optimal parameters for machining nickel basedalloys were chose.Under the optimal parameters above,wear and tool life werecompared among the uncoated inserts,PVD coated inserts and CVD coatedinserts,and then computer simulation technology was used to verify the test results.Finally,the paper focused on the efficiency of machining high-pressure outercasing in nuclear power,and aimed at the problems which were in the process ofmachining,such as: low efficiency of machining the connection through holes inthe horizontal flange,low efficiency but high difficulty in removing thehydraulic-test plates on the exhaust ports of the outer casing,and the poor qualityof taper pin holes’ in the horizontal flange.Through a series of technical research and discussion,and with the processoptimization,the problems above were solved, the machining efficiency wassignificantly improved, the production cost was reduced.The study providedtechnical supports for efficiently machining high-pressure outer casing in nuclearpower.