摘要
采用Gleeble1500热模拟机对38CrMoAl合金结构钢连铸坯在600~1350℃温度范围内的高温力学性能进行了测试,借助扫描电镜观察了高温拉伸后的断口形貌,结合断口金相组织形貌观察分析了断口断裂机理,系统分析了不同温度下钢的应力-应变曲线、高温强度及热塑性情况。结果表明,38CrMoAl合金结构钢连铸坯在高温温度区域发生了动态再结晶,增加了软化的作用,钢的塑性迅速提高,未发现第Ⅰ脆性区,第Ⅲ脆性区为600~1089℃,主要是由于AlN第二相粒子沿晶界析出和奥氏体向铁素体转变优先在晶界处析出了薄膜状α铁素体导致。通过对钢的高温力学性能研究,确定了易发生裂纹缺陷的脆性温度范围,为制定连铸二次冷却过程各种工艺参数提供了重要基础依据。
The high-temperature mechanical properties of 38CrMoAl alloy structural steel continuous casting billets were tested using a Gleeble1500 thermal simulator in the temperature range of 600~1350℃.The fracture morphology after high-temperature stretching was observed using scanning electron microscopy,and the fracture mechanism was analyzed by observing the metallographic structure morphology.The stress-strain curves,high-temperature strength,and thermoplastic properties of the steel at different temperatures were systematically analyzed.The results showed that dynamic recrystallization occurred in the continuous casting billet of 38CrMoAl alloy structural steel at high temperature,increasing the softening effect,and the plasticity of the steel rapidly improved.The first brittle zone was not found,and the third brittle zone was between 600 and 1089℃.This was mainly due to the precipitation of AlN second phase particles along grain boundaries and the preferential transformation of austenite to ferrite,which precipitated thin films at grain boundariesαcaused by ferrite.By studying the high-temperature mechanical properties of steel,the brittle temperature range prone to crack defects has been determined,providing an important basis for formulating various process parameters for the secondary cooling process of continuous casting..
作者
刘少伟
贺书明
宋志宇
刘青
Liu Shaowei;He Shuming;Song Zhiyu;Liu Qing(No.2 Steel-Making and Rolling Plant,Anyang Iron and Steel Group Co.,Ltd,Anyang 455004,Henan,China;State Key Laboratory of Advanced Metallurgy of Beijing Science and Technology University,Beijing 10083,China)
出处
《特钢技术》
CAS
2023年第3期8-12,共5页
Special Steel Technology
关键词
38CrMoAl
连铸坯
高温力学性能
断裂机理
38CrMoAl
continuous casting billet
high temperature mechanical properties
fracture mechanism
作者简介
刘少伟(1992年10月-),男,硕士,工程师,2018年1月北京科技大学冶金工程专业,现供职于安阳钢铁集团有限责任公司,主要研究方向为连铸,Email:liushaoweiustb@qq.com。
