Ti--Mg复合脱氧对钢热影响区组织和冲击性能的影响  

Effect of Ti- Mg complex deoxidation on the microstructure and impact properties of HAZ in steel

作　　者：宋明明[1,2] 宋波[1,2] 胡春林[3] 辛文彬[1,2] 宋高阳[1,2] 

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]北京科技大学冶金与生态工程学院,北京100083 [3]马鞍山钢铁股份有限公司第三钢轧总厂,马鞍山243011

出　　处：《工程科学学报》2015年第7期883-888,共6页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51274269);中央高校基本科研业务费资助项目(FRF-SD-12-010A;FRF-SD-12-010B)

摘　　要：利用Gleeble-1500热模拟试验机进行焊接热模拟实验,研究16Mn钢经微Ti和Ti-Mg处理后焊接热影响区组织及冲击性能的变化,并利用扫描电镜和能谱分析法观察和分析实验钢的夹杂与冲击断口形貌.Ti和Ti-Mg复合处理试样的热影响区显微组织分别主要是晶界块状铁素体+晶界侧板条铁素体和晶内针状铁素体+晶界块状铁素体.经Ti处理后钢中夹杂物主要为5μm左右的Ti Ox+Mn S复合夹杂,经Ti-Mg复合脱氧后钢中夹杂物主要为2μm左右Ti-Mg-O+Mn S组成的复合夹杂,且后者明显细化了钢中夹杂物尺寸.Ti-Mg复合脱氧试样中存在大量细小夹杂颗粒,一方面可钉扎裂纹,另一方面诱导形成了使大量针状铁素体,大焊接热输入条件下Ti-Mg复合脱氧试样热影响区冲击韧性明显强于单独Ti处理的试样.The effects of micro Ti and Ti- Mg on the microstructure and impact properties of welding heat affected zones（ HAZ）in 16 Mn steel were studied by welding thermal simulation on a Gleeble- 1500 hot simulator. The composition of inclusions and the Charpy impact fracture morphologies of the test steels were analyzed by scanning electron microscopy with energy dispersive spectrometry. The microstructures of HAZ in the Ti and Ti-Mg treated steels are mainly grain boundary allotriomorphic ferrite（ GBF） ＋ ferrite side plate（ FSP） and GBF ＋ intragranular acicular ferrite（ IAF）,respectively. Inclusions in the HAZ of the Ti-treated steel are Ti Ox＋ Mn S with the size of about 5 μm,while inclusions in the HAZ of the Ti-Mg treated steel are Ti-Mg-O ＋ Mn S with the size of about 2 μm. The particle size of the latter tested steel is smaller than that of the former one significantly. The HAZ of the Ti-Mg-treated steel has a lot of fine particles which pin cracks and induce the formation of a large number of IAF,leading to that the impact properties of the Ti- Mg-treated steel is better than those of the Ti-treated steel after experiencing large heat input welding.

关 键 词：碳锰钢 脱氧 热影响区 显微组织 冲击性能 针状铁素体 热模拟 

分 类 号：TG142.1[一般工业技术—材料科学与工程]