含0.23%Cr的20MnSiV高强钢筋强化机理及耐蚀性能

通过拉伸测试、金相组织观察、扫描电子显微观察及在模拟Cl^-环境和模拟工业大气环境中的72 h周浸腐蚀试验,研究了少量Cr（0.23%Cr）对20MnSiV Φ12 mm高强钢筋的微观组织、力学性能及耐蚀性能的影响。结果表明,0.23%Cr的加入,晶粒得到细化,晶粒度由8.5～9.0级提高到9.0～9.5级,同时截面珠光体分布更均匀,芯部区域和表面附近区域珠光体含量差由7.24%减小到3.22%。钢中加入0.23%Cr,达到了节“V”的目的,在保证力学性能的情况下,V含量降低了约0.01%。此外,0.23% Cr钢筋在工业大气环境中耐蚀性能得到改善,但少量Cr降低了钢筋在Cl^-环境中的耐蚀性能。

Strengthening Mechanism and Corrosion Resistance of 20MnSiV High Strength Steel Rebar Containing 0.23%Cr

^-Through tensile test, metallographic observation, scanning microscope observation and 72 h corrosion tests in simulated Cl environment and simulated industrial atmospheric environment, the effects of adding 0. 23% Cr on the microstructure and mechanical properties and corrosion resistance of Φ12 mm 20MnSiV high strength reinforced steel are studied. The results show that the grain size is refining obviously with 0. 23% Cr addition, and the grain size rating increase from 8. 5 ~9. 0 to 9. 0 ~ 9. 5, meanwhile the distribution of pearlite is more uniform, and the difference of pearlite content between internal region and the region near the surface decreases from 7. 24% to 3. 22%. With the addition of 0. 23%Cr, the element "V" can be saved, under the prerequisite for mechanical property guaranteed, vanadium contents decrease by about 0. 01%. Furthermore, the corrosion resistance of rebar with 0. 23% Cr is improved in industrial atmosphere environment ,however, adding small amount Cr the resistance property to chloride ions environment of steel rebar decreases slightly.