| Control rod drive mechanism is an important equipment of nuclear power plant,which is related to the normal operation and safety production of nuclear reactor.As the key transmission parts of the magnetic circuit in the driving mechanism,the mechanical properties and magnetic properties are the direct factors to ensure its safe operation.In order to make the material have good mechanical and magnetic properties at the same time,this thesis optimizes the heat treatment process of 0Cr13 Stainless steel to obtain a good match between mechanical properties and magnetic properties.0Cr13 Stainless steel belongs to ferrite and Martensite Duplex Stainless steel,which has certain magnetic properties and strength value.By adjusting the heat treatment process of 0Cr13 Stainless steel,to study the different tempering and annealing process on the comprehensive mechanics performance of the 0cr13 stainless steel,magnetic and the influence of the microstructure,The samples with good mechanical and magnetic properties were selected for 350℃high temperature performance test,and the matching of high temperature mechanical properties and magnetic properties was studied.The results show that the strength and hardness increase and the maximum magnetic induction intensity decreases with the increase of quenching temperature.When the tempering time is prolonged,the strength and hardness are reduced,which has little effect on the maximum magnetic induction strength.After quenching and tempering at 890℃,the yield strength reaches 252MPa,and after quenching and tempering at 1010℃,the yield strength reaches 330MPa;The change trend of the maximum magnetic induction intensity is opposite to the mechanical properties.The maximum magnetic induction intensity of the sample steel quenched and tempered at 890℃is the highest,and B_S=1.57T under the action of 8000A/m external magnetic field.The maximum magnetic induction intensity of the sample steel quenched and tempered at 1010℃decreases,and B_S=1.48T under the action of 8000A/m external magnetic field.In addition,the tempering state also has a great influence on the magnetism.The maximum magnetic induction intensity of the sample not tempered at 980℃is only 1.24T,while the maximum magnetic induction intensity of the sample after tempering is about 1.54T.Therefore,the quenched sample must be tempered to make the material have excellent magnetic parameters.In the annealing process,strength and hardness of the material values decline,with the increase of annealing temperature and time of temperature on the strong degree of influence is more obvious.At the same annealing time of 3h,after annealing at 740℃,the yield strength is 341MPa,and after annealing at 820℃,the yield strength decreases to214MPa,and the strength decreases by about 100MPa;Under the same annealing condition at 820℃,the 1h yield strength is 214MPa and 3h yield strength is 190MPa,and the strength decrease is not obvious.The maximum magnetic induction intensity is not affected by annealing temperature and duration.Generally,the maximum magnetic induction intensity is maintained at about 1.54T.Under the condition of 350℃high temperature test,the effect on mechanical properties is that the strength of the material decreases significantly,the tensile strength decreases by about 100MPa,the yield strength decreases by about 50MPa,and the effect on plasticity is not obvious;The effect of 350℃on magnetic properties is that the maximum magnetic induction intensity decreases,the permeability increases and the coercivity decreases.The maximum magnetic induction intensity at 350℃is generally about 1.52T.Compared with the two processes,quenching and tempering process:890℃×1h quenching+725℃×The sample tempered for 2h has good comprehensive mechanical and magnetic properties at 350℃.. |
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