嗜酸氧化亚铁硫杆菌腐蚀对Q235碳钢力学性能的影响

Influence of Acidithiobacillus Ferrooxidans Corrosion on the Mechanical Properties of Q235 Carbon Steel

为了揭示嗜酸氧化亚铁硫杆菌腐蚀对Q235碳钢的腐蚀程度和影响规律,以实现有效的生物去除加工,利用电子扫描电镜(Scanning Electron Microscopy,SEM)、电子万能拉伸试验机和冲击试验机等分析仪器,采用试验研究和理论分析的方法,对嗜酸氧化亚铁硫杆菌腐蚀作用下的Q235碳钢的抗拉强度、冲击韧性、微观组织等进行了测试和分析。研究表明:嗜酸氧化亚铁硫杆菌对Q235碳钢具有高效吞噬腐蚀作用,在30 d腐蚀周期内其试样尺寸和抗拉强度明显下降;嗜酸氧化亚铁硫杆菌腐蚀,主要是其引起材料横截面面积减小,导致材料有效承载能力降低,但并不会使材料的延伸率和冲击功降低;嗜酸氧化亚铁硫杆菌没有使Q235碳钢发生韧脆转变,可利用嗜酸氧化亚铁硫杆菌菌种实现对Q235碳钢有效的生物去除加工。

To reveal the corrosion and influence law of acidithiobacillus ferrooxidans on Q235 carbon steel and achieve effective biological removal process,the Scanning Electron Microscopy( SEM),electronic universal tensile testing machine,impact testing machine and other analysis methods are used to test and analyze the tensile strength,impact toughness and microstructure of Q235 carbon steel to determine its corrosion behavior and mechanical properties. Experimental and theoretical analysis methods are adopted. The results show that acidithiobacillus ferrooxidans produces the serious corrosion on Q235 carbon steel. The tensile strength is obviously reduced after 30 d. The main corrosion effect of acidithiobacillus ferrooxidans on the mechanical properties of materials is to cause the cross sectional area of material decreased and the material effective load bearing capacity reduced. But the microbial corrosion does not reduce the elongation and impact energy of the Q235 carbon steel. It reveals by SEM observation that the fracture surfaces of tensile and impact samples have the characteristics typical of ductile fracture. This suggests that acidithiobacillus ferrooxidans does not result in ductile brittle transition of Q235 carbon steel. So,acidithiobacillus ferrooxidans can be used for Q235 carbon steel effective biological removal machining.