静态载荷下非调质钢高强螺栓的变形行为  

Deformation behavior of non heat-treated steel high strength bolts under static load

作　　者：罗志俊[1,2] 李舒笳[1] 孙齐松[1,2] 马跃[1] 王晓晨[1] 王猛[1] 王丽萍[1] 

机构地区：[1]首钢技术研究院,北京100043 [2]绿色可循环钢铁流程北京市重点实验室,北京100043

出　　处：《材料热处理学报》2016年第11期118-122,共5页Transactions of Materials and Heat Treatment

摘　　要：利用保证载荷及透射电镜（TEM）的试验方法,分析了铁素体＋马氏体双相（F＋M）组织及铁素体＋珠光体（F＋P）组织在静态载荷下对高强螺栓永久变形行为的影响。结果表明：F＋P组织高强螺栓时效前永久伸长量达到15μm以上,时效后大幅度下降至不高于5μm;铁素体-马氏体类型非调质螺栓时效前后永久伸长量变化较小,均为1~2μm。在200~400℃范围内时效处理,F＋P类型和F＋M类型非调质钢螺栓强度先增加后减小,在250~300℃时达到峰值,但均高于未时效处理螺栓。铁素体内部大量的相互缠结的位错以及胞状亚结构（亚晶粒）是铁素体-马氏体双相钢螺栓时效前后永久伸长变化较小的原因。螺栓制造过程中的拉拔变形诱导析出纳米尺寸的细小碳化物或氮化物阻碍位错运动和沉淀强化是时效后强度变化的原因。Effect of ferrite-martensite dual phase（ F ＋ M） structure and ferrite-pearlite（ F ＋ P） structure on high-strength bolts permanent deformation behavior under static load was investigated by utilizing transmission electron microscopy（ TEM） and proof load.The results indicate that elongation of the high-strength bolts with ferrite-pearlite（ F ＋ P） structure is 15 μm or even bigger before aging,while it declined to no more than 5 μm after aging. However,in the case of non-heat-treated high-strength bolts with ferrite-martensite structure,the permanent elongation has small change before and after aging. When aging treatment is in the range of 200-400 ℃,the strength of both F ＋ P and non-heat-treated F ＋ M bolts increases first and then decreases and reaches a peak value at 250-300 ℃,but is higher than that of the without aging treatment bolts. Reasons of small changes in permanent elongation before and after aging are cellular substructure（ subgrains） and a lot of entangled dislocation inside ferrite. After aging the strength variation is caused by precipitation of fine disperse nitrides or carbides which impede dislocation motion in drawing deformation of the bolt manufacturing process.

关 键 词：非调质钢 铁素体-马氏体组织 高强螺栓 静态载荷 永久伸长 

分 类 号：TG142.24[一般工业技术—材料科学与工程]