激光表面处理对316不锈钢微观组织和性能的影响

发布时间：2018-05-22 12:18

本文选题：316不锈钢 + 冷轧　；参考：《燕山大学》2015年硕士论文

【摘要】：本文采用二辊轧机和激光处理设备对316不锈钢进行冷轧和激光表面处理,通过金相、X射线衍射、硬度及电化学等方法探究激光处理对固溶态和冷轧态316不锈钢微观组织和性能的影响。研究结果表明:316不锈钢经过冷轧后显微硬度随着轧制变形量的增加逐渐增大,轧制变形量50%时组织中出现形变诱发马氏体,此后变形量增大马氏体含量增多。冷轧使得316不锈钢的点蚀电位下降,增大了其晶间腐蚀敏感性,但是点蚀发生后钝化膜的修复能力增强。固溶态316不锈钢经过激光处理后晶粒内部发生滑移,随激光处理温度升高和次数增大,层错概率、位错密度、微应变及显微硬度增大,但孪晶概率和微晶尺寸下降,晶粒内部形成了许多小角度晶界。激光处理降低了固溶态316不锈钢的点蚀电位,但增强了点蚀发生时钝化膜的修复能力,固溶316不锈钢激光处理后的晶间腐蚀敏感性增大。冷轧态(变形量80%)316不锈钢经过激光处理后发生了马氏体向奥氏体的逆转变。随激光处理的温度升高和次数增大,层错概率、位错密度、微应变和微晶尺寸减小,激光处理区的显微硬度下降。激光处理提高了冷轧态316不锈钢的点蚀电位但使钝化膜的修复能力减弱,经过激光处理后冷轧态不锈钢的晶间腐蚀敏感性降低。
[Abstract]:In this paper, the cold rolling and laser surface treatment of 316 stainless steel were carried out by two high rolling mill and laser treatment equipment, and the X-ray diffraction of 316 stainless steel was carried out by metallographic X-ray diffraction. The effect of laser treatment on microstructure and properties of 316 stainless steel in solid solution and cold rolled state was investigated by means of hardness and electrochemistry. The results show that after cold rolling, the microhardness increases gradually with the increase of rolling deformation, and the deformation induced martensite appears in the microstructure at the rolling deformation rate of 50 and the content of martensite increases thereafter. Cold rolling decreases the pitting potential of 316 stainless steel and increases its sensitivity to intergranular corrosion, but the repair ability of the passivation film increases after pitting. After laser treatment, the grain slip occurs in 316 stainless steel. With the increase of temperature and times of laser treatment, the probability of stacking fault, dislocation density, microstrain and microhardness increase, but the twin probability and microcrystalline size decrease. Many small angle grain boundaries are formed inside the grains. Laser treatment reduced the pitting potential of the solution 316 stainless steel, but enhanced the repair ability of the passivation film during the pitting corrosion. The intergranular corrosion sensitivity of the laser treated 316 stainless steel was increased. After laser treatment, the reverse transformation of martensite to austenite occurred in cold-rolled stainless steel (80 and 316 stainless steel). With the increase of temperature and times of laser treatment, the probability of stacking fault, dislocation density, microstrain and microcrystalline size decrease, and the microhardness of laser treatment region decreases. The pitting potential of cold-rolled 316 stainless steel was increased by laser treatment, but the repair ability of passivation film was weakened, and the intergranular corrosion sensitivity of cold-rolled stainless steel decreased after laser treatment.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG665;TG142.71

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