Relationship between crystallographic structure of complex inclusions MgAl_(2)O_(4)/Ti2O_(3)/MnS and improved toughness of heat-affected zone in shipbuilding steel  

作　　者：Yan Wang Li-guang Zhu Jin-xia Huo Qing-jun Zhang Yao-guang Wu Wei Chen Shuo-ming Wang 

机构地区：[1]College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,Hebei,China [2]College of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,Hebei,China [3]China Analysis and Testing Center,North China University of Science and Technology,Tangshan 063210,Hebei,China [4]MCC Capital Engineering&Research Incorporation Limited,Metallurgical Engineering Consulting and Design Division,Beijing 100176,China

出　　处：《Journal of Iron and Steel Research International》2022年第8期1277-1290,共14页

基　　金：support from the National Natural Science Foundation of China(Nos.52004094 and 51874137);the Hebei Province Natural Science Fund Project(E2021209037.E2020209044,_and E2020209036);Fundamental Innovation Team of High Quality Clean Stcel in Tangshan_fromTangshan Scienceand Technology Bureau(21130209D).

摘　　要：In accordance with the minimum degree of disregistry mechanism in oxide metallurgy, the intragranular acicular ferrite (IAF) generated by microalloying elements in austenite was studied. Herein, the effect of Mg treatment on the microstructure and toughness of the heat-affected zone (HAZ) in shipbuilding steel was investigated. Mg treatment produced inclusions that influenced the formation of acicular ferrite in the microstructure. This refined the HAZ microstructure and improved its toughness. Electron backscatter diffraction was used to determine the oxides of titanium and the MgO Al_(2)O_(3) or MgAl_(2)O_(4) complex inclusions that induced the formation of IAF. MnS precipitated on MgAl_(2)O_(4) on a specific habit plane and in a specific direction. MnS had a specific orientation relationship with MgAl_(2)O_(4), i.e., f100gMgAl_(2)O_(4) //{100}MnS. The 35-mm-thick plate obtained in the industrial test after welding at a welding heat input of 120 kJ/cm had an average impact absorbed energy of 282.7 J at - 40 ℃ and 2 mm from the weld joint in the HAZ. The twodimensional disregistry index between inclusions can be used as the basis for controlling their distribution and adsorption force. Microalloy addition in the order of Al-Mg-Ti is key to obtaining abundant dispersion and fine nucleation in austenite.

关 键 词：High heat input welding Mg treatment Disregistry mechanism Heat-affected zone 

分 类 号：TG142[一般工业技术—材料科学与工程]