Effect of titanium treatment on inclusions and microstructure in EH36 shipbuilding steel
LUO Deng1, HONG Zhi-wei2, LI Li3, LI Jian3, YANG Li3, ZHANG Xue-wei3
1. Xiangtan Iron and Steel Co., Ltd. of Hunan Valin, Xiangtan 411101, Hunan, China; 2. Zhongkexin Engineering Consulting (Beijing) Co., Ltd., Beijing 100039, China; 3. Institute for Engineering Steel, Central Iron and Steel Research Institute, Beijing 100081, China
Abstract：In order to study the influence of titanium treatment (the mold feeding titanium wire) on inclusions in EH36 steel,the size,composition and three-dimensional morphologies of inclusions in EH36 shipbuilding steel were obtained by electrolytic extraction method using non-aqueous electrolytes combined with SEM method. The experimental results show that the Ca-Si-Al system oxide inclusion+MnS in the steel was transformed into Ca-Si-Al-Ti system oxide inclusion+MnS after feeding the titanium wire in the mold,and the three-dimensional surfaces of them changes from smoother to rough and porous. After the welding thermal simulation,the microstructure had transformed from the grain boundary ferrite and side slatted ferrite in a titanium-free sample into acicular ferrite in the containing titanium specimen. What is more,the morphology of ferrite around the inclusion was transformed from block into acicular,the toughness was increased by 70 J. The forming conditions of titanium oxide inclusions in shipbuilding steel were analyzed by the thermodynamic calculation. The calculation results show that there was a competitive relationship between titanium and aluminum which react with oxygen to form oxide. The mass percent of aluminum should be strictly controlled not more than 0.003 5% in liquid steel when the mass percent of Ti was 0.02% in steel. Thus,so as to ensure that a substantial amount of titanium-containing oxide particles could be generated in liquid steel.
罗登, 洪志伟, 李丽, 李健, 杨丽, 张学伟. 钛处理对EH36船板钢中夹杂物及组织特征影响[J]. 钢铁, 2020, 55(7): 65-71.
LUO Deng, HONG Zhi-wei, LI Li, LI Jian, YANG Li, ZHANG Xue-wei. Effect of titanium treatment on inclusions and microstructure in EH36 shipbuilding steel[J]. Iron and Steel, 2020, 55(7): 65-71.
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2020, Vol. 55 
