Evolution of inclusions in high heat input welding steel with Ti-Ca compound deoxygenation
LI Chao1， DONG Ting-liang1， KONG Wei-ming1， LI Jian-xin1， LI Yu-qian2， LI Jie1，3
（1. Technology Research Institute， HBIS Group， Shijiazhuang 050023， Hebei， China； 2. Hansteel Company， HBIS Group， Handan 056015， Hebei， China； 3. School of Metallurgical and Ecological Engineering， University of
Science and Technology Beijing， Beijing 100083， China）
Abstract：In order to better master the production process of oxide metallurgy，the evolution law of the composition， size and quantity of inclusions in the high heat input welding steel full production process with the Ti-Ca composite deoxygenation was studied by industrial experiments and thermodynamic calculations. At the beginning of the LF refining， the main type of inclusions was silicon manganese oxide； after the Ti-Ca compound deoxygenation， it changed into CaO-Al2O3-TiOx-MgO-SiO2； the mass percent of Al in the refining process decreased， while the mass percent of Ca and Ti increased； in the final steel plate， the typical styles of inclusions were CaO-Al2O3-SiO2， CaO-Ti2O3， Ca（Mn）S， TiN composite polyphase. In the whole refining process of LF-RH， the integral number of inclusions decreased continuously， while the tendency of the continuous casting process was opposite； the volume percent of inclusions in the final steel plate was about 2.6×10－5. The effect of Ti-Ca compound deoxygenation and RH refining on inclusions evolution was obvious； the percentage of 0-1 μm inclusions in the plate was about 73%， while that of ＞3 μm inclusions was only ab- out 5%. After 100 and 200 kJ/cm line energy welding simulations， the average impact work values at －40 ℃ of HAZ were 275 and 209 J respectively； acicular ferrites with a core of inclusions were found after corrosion.
李 超， 董廷亮， 孔维明， 李建新， 李玉谦， 李 杰. Ti-Ca复合脱氧大线能量焊接用钢中夹杂物的演变[J]. 钢铁, 2019, 54(2): 35-40.
LI Chao1， DONG Ting-liang1， KONG Wei-ming1， LI Jian-xin1， LI Yu-qian2， LI Jie1，3. Evolution of inclusions in high heat input welding steel with Ti-Ca compound deoxygenation. Iron and Steel, 2019, 54(2): 35-40.
2019, Vol. 54 
