喷丸强化对超高强度钢耐腐蚀性能的影响

Effect of Shot Peening on Corrosion Resistance of Ultra-high Strength Steel

目的提高舰载机结构疲劳关键部位的主体材料超高强度钢的耐蚀性能。方法基于实测的环境数据编制加速腐蚀试验环境谱,针对喷丸和未喷丸超高强度钢试验件在实验室条件下开展加速腐蚀试验,从宏观/微观形貌、质量损失、腐蚀速率和表面粗糙度等方面表征腐蚀行为,分析讨论喷丸强化对超高强度钢耐腐蚀性能的影响。结果超高强度钢腐蚀初期为局部点蚀,然后转变为全面均匀腐蚀。喷丸强化延缓了腐蚀形态转变的时机,喷丸试验件腐蚀速率约为未喷丸试验件的75%,加速腐蚀当量为3 a,未喷丸和喷丸试验件表面平均粗糙度分别为5.67mm和4.16mm,前者为后者的1.36倍。结论通过质量损失率、腐蚀速率和表面粗糙度的对比分析知,喷丸强化明显提高了超高强度钢的耐腐蚀性能。

The paper aims to improve the corrosion resistance of ultra-high strength steel which is used as the main material for critical fatigue part of shipborne aircraft structure.Based on the measured environmental data,the environmental spectrum of accelerated corrosion test was compiled.The accelerated corrosion test was carried out under laboratory conditions for shot peening and un-peened ultra-high strength steel specimens.The corrosion behavior was characterized from macro/micro morphology,weight loss,corrosion rate and surface roughness.The effect of shot peening on corrosion resistance of ultra-high strength steel was analyzed and discussed.The results showed that the initial corrosion stage of ultra-high strength steel was local pitting corrosion,and then transformed into overall uniform corrosion.Shot peening delayed the transformation of corrosion morphology.The corrosion rate of shot peened test piece was about 75%of that of non-shot peened test piece.When the accelerated corrosion time was equivalently 3 a,the average surface roughness of un-peened specimens and shot peened specimens was 5.67μm and 4.16μm respectively,the former was 1.36 times of the latter.Through the comparative analysis of weight loss rate,corrosion rate and surface roughness,it is found that shot peening significantly improves the corrosion resistance of ultra-high strength steel.