退火时间对Fe-2.0Mn-4.7Al-0.4C低密度高强度钢组织和性能的影响  

Effect of annealing time on microstructure and properties of Fe-2.0Mn-4.7Al-0.4C low density high strength steel

作　　者：彭侠超 唐恩 张香云[1] Peng Xiachao;Tang En;Zhang Xiangyun(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou Gansu 730050,China;College of Optoelectronic Manufacturing,Zhejiang Industry&Trade Vocational College,Wenzhou Zhejiang 325003,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]浙江工贸职业技术学院光电制造学院,浙江温州325003

出　　处：《金属热处理》2024年第11期112-117,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(52061024,52161027);甘肃省自然科学基金(21JR7RA260);兰州理工大学红柳优秀青年人才支持计划。

摘　　要：通过JMat-Pro模拟软件确定了Fe-2.0Mn-4.7Al-0.4C低密度钢退火温度为860℃,通过光学显微镜、扫描电镜、电子万能材料试验机等检测方法研究了退火时间对热轧态Fe-2.0Mn-4.7Al-0.4C钢的组织及力学性能的影响。结果表明,热轧态Fe-2.0Mn-4.7Al-0.4C钢经过退火处理,其组织由δ铁素体、α铁素体、马氏体、珠光体和渗碳体转变为δ铁素体、珠光体和残留奥氏体。退火保温120 min时,拉伸断口形貌显示试样由脆性断裂转变为韧性断裂,材料抗拉强度为515.6 MPa,屈服强度为361.0 MPa,伸长率达到最大值35.4%,强塑积达到18.3 GPa·%,综合力学性能达到最好。而退火时间过长,达到180 min时,组织晶粒长大并发生聚集,位错运动消失,导致材料韧性降低,增加了材料的脆性,断口以韧窝和较为平滑的解理面为主。Annealing temperature of Fe-2.0Mn-4.7Al-0.4C steel was determined to be 860℃by using JMatPro simulation software.The effect of annealing time on the microstructure and mechanical properties of the hot-rolled Fe-2.0Mn-4.7Al-0.4C steel was studied by means of optical microscope,scanning electron microscope,and electronic universal material testing machine.The results show that after annealing treatment,the microstructure of the hot-rolled Fe-2.0Mn-4.7Al-0.4C steel transforms fromδferrite,αferrite,martensite,pearlite,and cementite toδferrite,pearlite,and retained austenite.When annealed for 120 min,the tensile fracture morphology of the specimen shows a transition from brittle fracture to ductile fracture.The tested steel has the best comprehensive mechanical properties with tensile strength of 515.6 MPa,yield strength of 361.0 MPa,maximum elongation of 35.4%,and strength-elongation product of 18.3 GPa·%.However,when the annealing time is too long to reach 180 min,the grain grows and aggregates,the dislocation movement disappears,resulting in a decrease in material toughness and an increase in material brittleness.The fracture surface is mainly composed of ductile dimples and relatively smooth cleavage surfaces.

关 键 词：低密度钢 退火时间 断口形貌 显微组织 力学性能 

分 类 号：TG142[一般工业技术—材料科学与工程]