Microstructure evolution of 400 MPa class rebar produced by QST and VNM technology under the high strain and low cycle fatigue
Microstructure evolution of 400 MPa class rebar produced by QST and VNM technology under the high strain and low cycle fatigue
复制标题
QST和VNM技术生产的400 MPa级钢筋在高应变和低周疲劳下的微观组织演变
DOI：
10.1016/j.conbuildmat.2019.116889
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发表时间：
2019-12-30
影响因子：
7.4
通讯作者：
Chen, Jian
中科院分区：
文献类型：
--
作者：
Lv, Yukun;Zhao, Xuerou;Chen, Jian
400 MPa级热轧钢筋作为建筑材料被广泛应用。目前生产这种钢筋的主要工艺有钒氮微合金化（VNM）和淬火自回火（QST）。在高应变低周疲劳（HSLCF）载荷下，系统研究了两种钢筋的组织演变和性能。为了评价高强混凝土的能量吸收率，提出了一种新的循环韧性模型。结果表明，QST钢筋在+/-1%应变幅范围内表现出较大的循环软化速率，其原因是表层淬火和自回火马氏体组织中产生二次裂纹，形成较大的位错胞结构。此外，由于VNM钢筋在循环硬化阶段具有较高的位错密度和较小的位错胞结构，因此VNM钢筋具有较高的循环韧性（15 A J/cm（3）），表明VNM钢筋的HSLCF性能远优于QST钢筋。(C)2019爱思唯尔有限公司版权所有。
The 400 MPa grade hot rolled rebar are widely used as the construction and building materials. The main produced technologies for this rebar are V-N Microalloyed (VNM) and Quenched and Self-Tempered (QST). Under the high strain and low cycle fatigue (HSLCF) loading, the microstructure evolution and performance of above two types of rebars were investigated systematically. In order to evaluate the rate of energy-absorption under HSLCF, a new model named cyclic toughness was proposed. The results show that QST rebar exhibit greater rate of cyclic softening over +/- 1% strain amplitude, which caused by the secondary cracks in the quenched and self-tempered martensite microstructure of surface layer and the formation of larger dislocation cell structure. Additionally, VNM rebar had higher cyclic toughness (15A J/cm(3)) due to higher dislocation density and smaller dislocation cell structure in the cyclic hardening stage, which indicate that the HSLCF performance of VNM rebar are much better than QST rebar. (C) 2019 Elsevier Ltd. All rights reserved.