The Effects Of Proton Irradiation On Microstructure And Mechnical Properties Of2Cr13and40Cr

2Cr13stainless steel and40Cr steel can be made of some space mechanism parts,such as manipulator、gears and shafting in inter-satellite link drive for its excellentmechanical properties after thermal refining. Some devices often exposed to the spaceenvironment directly when serving in space orbit. The irradiation of charged particlesin space environment could influence the microstructure and mechanical properties ofmaterials to varying degrees, and further resulting in unstable performance.In this work,2Cr13and40Cr were treated separately by different heat treatmentprocesses firstly. Then the samples for tensile,XRD and TEM test were manufacturedand then listed into a mold. After that,they were irradiated under the vacuum state atroom temperature with three irradiation fluences:2×1014Protons·cm-2,2×1015Protons·cm-2,2×1016Protons·cm-2. Finally, the microstructure and mechanicalproperties of2Cr13and40Cr were investigated by XRD,SEM,TEM and INSTRONdrawing machine before and after irradiation, respectively. The tansport of protons in2Cr13、40Cr was simulated by positive ion transport simulation program TRIM-2008as a supplyment.The results showed that, no phase transition was observed on the surface of2Cr13and40Cr after irradiation. The macroscopic mechanical properties and tensilefracture mechanisms did not change under irradiation conditions in this work. TheTEM observation revealed that the number of dislocations and the nano-indentationhardness increased after proton irradiation in annealed2Cr13. The number ofdislocations decreased and the size of precipitation increased in the tempered2Cr13.The nano-hardness decreased relevantly. There were no observable changes ofmicrostructure of40Cr. But the Young modulus and nano-indentation hardness of40Cr increased obviously.Through the experimental results and simulation results analysis, it appeared thatthe proton irradiation resulted in a large number of point defects within2Cr13,40Cr, in favor of atomic motion, mainly promoting the formation of new dislocations andprecipitates. At this point, the increasing density of defects with small size results inirradiation hardening. As the number of point defects is further increasing, the densityof defects decreases and the size grows in favor of the movement of defects, At thispoint, proton irradiation causes irradiation soften. The results of this paper make abeneficial exploration to the study of irradiation on2Cr13and40Cr, demonstratingthat the irradiation by charged particles can change the material surface properties.