热镀锌工艺对高Si系DH780钢力学性能及显微组织的影响  

Effect of hot-dip galvanizing process on mechanical properties and microstructure of DH780 steel containing high Si

作　　者：王建平 富聿晶 左远鸿 Wang Jianping;Fu Yujing;Zuo Yuanhong(Department of Materials Science and Engineering,Yingkou Institute of Technology,Yingkou Liaoning 115014,China;Benxi Steel Plate R&D Institute of Anshan Iron and Steel Group,Benxi Liaoning 117000,China;Hot Rolling Mill,Bensteel Group Co.,Ltd.,Benxi Liaoning 117022,China)

机构地区：[1]营口理工学院材料科学与工程学院,辽宁营口115014 [2]鞍钢集团钢铁研究院本钢技术中心,辽宁本溪117000 [3]本钢集团有限公司热连轧厂,辽宁本溪117022

出　　处：《金属热处理》2023年第10期202-206,共5页Heat Treatment of Metals

基　　金：营口理工学院引进人才研究启动基金(110505010)。

摘　　要：针对含高Si热镀锌DH780钢进行了热模拟试验研究,热模拟工艺试验主要对材料缓冷温度以及快冷出口温度进行了相关试验,缓冷温度试验中将缓冷温度设定为740、720以及700℃,快冷出口温度试验主要将快冷出口温度设定为460、400以及350℃。研究表明,缓冷温度设定较高时材料的屈服强度明显提高,当缓冷温度设定为740℃及720℃时,材料抗拉强度基本维持不变,但当缓冷温度设定为700℃时,材料抗拉强度略有降低,主要是缓冷温度降低造成材料中铁素体含量提高,快冷冷却速率降低,从而造成材料中马氏体含量降低,抗拉强度降低;在快冷出口温度试验中发现,当快冷出口温度设定为460℃时材料强度级别得到保证,但断后伸长率值接近标准下限,当快冷出口温度为400℃时,材料强度出现明显下降,主要是因为材料中出现贝氏体,造成材料中马氏体含量不足,当快冷出口温度设定为350℃时,材料力学性能优良,材料中存在少量残留奥氏体,马氏体弥散分布,获得了良好的断后伸长率,从而保证材料的成形性能。Thermal simulation experiment on DH780 hot-dip galvanized high strength steel containing high Si was carried out.The thermal simulation experiment mainly focused on the slow cooling temperature and fast cooling outlet temperature of the material.In the slow cooling temperature experiment,the slow cooling temperature was set to 740,720 and 700℃,and the rapid cooling outlet temperature was set to 460,400 and 350℃.The results show that the yield strength of the material increases obviously when the slow cooling temperature is set high,and the tensile strength of the material remains basically unchanged when the slow cooling temperature is set at 740℃ or 720℃,but the tensile strength decreases slightly when the slow cooling temperature is set to 700℃.The main reason is that the decrease of slow cooling temperature leads to the increase of ferrite content and the decrease of fast cooling rate,which leads to the decrease of martensite content in materials.The tensile strength of the material is reduced.In the experiment of rapid cooling outlet temperature,it is found that the strength grade of the material is guaranteed when the rapid cooling outlet temperature is set at 460℃,but the elongation value is close to the standard lower limit,and the material strength decreases obviously when the rapid cooling outlet temperature is 400℃.It is mainly due to the appearance of bainite in the material,resulting in insufficient martensite content in the material.When the rapid cooling outlet temperature is set at 350℃,the material has excellent mechanical properties.There is a small amount of retained austenite in the material,and the martensite is dispersed,and good elongation is obtained so as to ensure the formability of the material.

关 键 词：热镀锌工艺 缓冷温度 快冷出口温度 马氏体 残留奥氏体 

分 类 号：TG174.4[金属学及工艺—金属表面处理]