【摘要】 研究了 0 0 5 %C 0 12 %Nb钢板 12 0 0℃固溶 ,10 %冰盐水处理 - 15 %冷轧变形 6 0 0～ 6 80℃时效时Nb对钢中板条马氏体再结晶行为的影响。试验结果得出在 6 0 0～ 6 80℃范围内 ,Nb能阻止变形马氏体组织的再结晶 ,时效组织主要为保持板条马氏体位向的回火索氏体 ,未发现粒状铁素体。该钢在固溶处理 +15 %冷变形 +6 4 0℃时效后的屈服强度为 712 5MPa ,抗拉强度 74 0 0MPa ,延伸率δ519 5 % ,而该钢经固溶处理 +6 4 0℃时效后的屈服强度为 4 90 0MPa ,抗拉强度 5 6 2 5MPa ,延伸率δ52 2 5 % ,发现未经 15 %冷轧变形的0 0 5 %C 0 12 %Nb钢在时效过程板条马氏体组织发生明显的相变再结晶 ,表明时效过程变形能促进Nb的碳氮化物弥散析出 ,阻止板条 马氏体相变再结晶 ,从而提高钢的强度。更多还原

【Abstract】 The effect of Nb on lath martensite recrystallization behavior in 0.05%C-0.12%Nb steel plate solid solution treated at 1 200 ℃, 10% ice salt-water cooling - 15% cold rolling deformed and 600～680 ℃ aged has been studied. The test results showed that Nb could prevent recrystallization of deformed lath martensite structure at 600～680 ℃, and the aged structure was tempered sorbite kept lath martensite phase direction with no ferrite particles discovered. The yield strength of the steel with solid solution treated + 15% cold deformation + 640 ℃ aged was 712.5 MPa, tensile strength 740.0 MPa and yield δ 5 19.5%, while the yield strength of the steel with solid solution + 640 ℃ aged was only 490.0 MPa, tensile strength 562.5 MPa and yield δ 5 22.5%. It was observed that the lath martensite structure occurred obviously phase transformation recrystallization in aged of 0.05C-0.12Nb steel with no cold rolling deformation. It indicated that deformation could promoted dispersed precipitation of carbo-nitride of Nb in aging to prevent phase recrystallization of lath martensite.更多还原