连续油管用低碳微合金钢控轧控冷显微组织与疲劳性能
Microstructure and fatigue properties of low carbon microalloyed coiled tubing steel after controlled rolling and cooling
黄志国 1李艳艳 2蒋波3
作者信息
- 1. 河北石油职业技术大学工业技术中心,河北承德 067000
- 2. 河北石油职业技术大学机械工程系,河北承德 067000
- 3. 北京科技大学材料科学与工程学院,北京 100083
- 折叠
摘要
为满足连续油管用低碳微合金钢强韧性要求的针状铁素体和贝氏体复相组织特征,通过设计控轧控冷生产工艺制备了 5.3 mm厚的连续油管用热轧板材.通过低周疲劳试验分析了热轧板材的低周疲劳性能,并对低周疲劳断口进行了观察,同时分析了热轧板的力学性能和显微组织.结果表明,采用终轧温度810℃、冷却速度为52℃/s、卷取温度为450℃生产的低碳微合金钢的疲劳寿命为3784周.低周疲劳断口的瞬断区形貌以韧窝为主,断裂方式属于韧性断裂.拟合得出的低周疲劳应变与疲劳寿命的关系公式有较好的拟合效果,可用于预测不同应变幅条件下的疲劳寿命.试验钢力学性能满足要求,显微组织为铁素体、贝氏体与M/A岛,其中铁素体体积分数约为74％,且主要以针状铁素体形式存在,使得试验钢具有良好的疲劳性能.
Abstract
In order to meet the strength and toughness requirements of low-carbon microalloyed steel for coiled tubings,a 5.3 mm thick hot-rolled plate for coiled tubing was prepared by designing controlled rolling and controlled cooling production process.The low cycle fatigue property of the hot rolled plate was analyzed by low-cycle fatigue test and the low-cycle fatigue fracture was observed.The mechanical properties and microstructure of the hot rolled plate were analyzed.The results show that the fatigue life of the tested steel is 3784 cycles when produced at final rolling temperature of 810 ℃,cooling rate of 52 ℃/s,and coiling temperature of 450 ℃.The morphology of the transient fracture zone of the low cycle fatigue fracture is mainly dimple,and the fracture mode belongs to ductile fracture.The fitted formula for the relationship between low cycle fatigue strain and fatigue life has a good fitting effect and can be used to predict fatigue life under different strain amplitude conditions.The mechanical properties of the tested steel meet the requirements,and the microstructure consists of ferrite,bainite,and M/A islands.The volume fraction of ferrite is about 74％,and mainly exists in the form of acicular ferrite,making the tested steel have good fatigue property.
关键词
连续油管/低碳微合金钢/控轧控冷/低周疲劳性能/疲劳断口Key words
coiled tubing/low carbon microalloyed steel/controlled rolling and cooling/low-cycle fatigue property/fatigue fracture引用本文复制引用
出版年
2024
NETL
NSTL
万方数据