经济型耐酸钢Q345NS的高温塑性研究  

Study on high temperature plasticity of economical acid resistant steel Q345NS

作　　者：汪飞 胡学文[1] 何博[1] 郭锐 徐雁[1] 闻成才[1] WANG Fei;HU Xuewen;HE Bo;GUO Rui;XU Yan;WEN Chengcai(Technology Center,Maanshan Iron&Steel Co.,Ltd.,Maanshan 243000,Anhui,China)

机构地区：[1]马鞍山钢铁股份有限公司技术中心,安徽马鞍山243000

出　　处：《四川冶金》2024年第6期26-30,共5页Sichuan Metallurgy

摘　　要：采用热模拟试验机、光学显微镜、扫描电镜分析了经济型耐酸钢Q345NS在0.2%Ni和无Ni两种成分设计下的高温塑性。结果表明,两种试验钢的高温塑性随温度变化规律相似,皆在700℃时高温塑性达到极大值后800℃时又达到极小值。Ni的添加对改善耐酸钢的高温塑性主要作用在第Ⅲ低温脆性区,0.2%Ni试验钢在700℃时的断面收缩率是无Ni试验钢的2倍,主要与0.2%Ni试验钢断口处铁素体组织更加细小均匀有关。800℃时两试验钢高温塑性较差与Cu等元素在晶界富集引起晶界偏析产生热脆现象有关。以上试验结果对铸坯矫直和吊运具有一定指导价值,如铸坯矫直过程中2000 mm和1500 mm两种典型坯宽分别采用0.8 m/min和1.05 m/min的拉速可降低耐酸铸坯角部裂纹风险,也应避免在600℃和800℃附近进行铸坯吊运。The high temperature plasticity of economical acid resistant steel Q345NS were analyzed using a thermal simulation testing machine,optical microscope,and scanning electron microscope under two composition designs of 0.2%Ni and Ni free.The results show that the high temperature plasticity of the two test steels have similar temperature variation patterns,with the high-temperature plasticity reaching its maximum at 700℃and then reaching its minimum at 800℃.The addition of Ni mainly improves the high-temperature plasticity of acid resistant steel in the third low-temperature brittle zone.The cross-sectional shrinkage of the 0.2%Ni test steel at 700℃is twice that of the non Ni test steel,mainly related to the finer and more uniform ferrite structure at the fracture surface of the 0.2%Ni test steel.The poor high-temperature plasticity of the two test steels at 800℃is related to the enrichment of Cu and other elements at grain boundaries,which causes grain boundary segregation and thermal embrittlement.The above experimental results have certain guiding value for the straightening and lifting of acid resistant steel billets.When the typical billet widths of 2000 mm and 1500 mm are straightened during the casting process,using a pulling speed of 0.8 m/min and 1.05 m/min respectively can reduce the risk of corner cracks in acid resistant castings,respectively.It should also be avoided to carry out slab lifting operations near 600℃and 800℃.

关 键 词：经济型 耐酸钢 镍 高温塑性 铸坯裂纹 

分 类 号：TG142.31[一般工业技术—材料科学与工程]