ZHANG Zuo-tai
,
ZHANG Ying-yi
钢铁研究学报(英文版)
The recrystallization and oxidation of a Mn-containing interstitial free (IF) steel were investigated simultaneously using confocal scanning laser microscope (CSLM) under controlled atmosphere of Ar 95% and H2 5% (in volume percent) at different temperatures. It was found that the grain boundary played a significant role in controlling recrystallization and oxidation in overall oxidation kinetics of the steel. The surface morphology was composed of two networks along the original and new grain boundaries respectively, which did not coexist. The grain boundary moved in different directions with different velocities during annealing process. The recrystallization processes were studied by CSLM motion video through observing the moving grain boundary to estimate the time for 50% recrystallization, and the activation energy for recrystallization was therefore calculated. The oxidation mechanism was discussed through comparison of the fluxes among mass transfer of water vapor, dissociation of water vapor and outward diffusion alloying elements. The results indicated that the oxidation was controlled by the mass transfer from the bulk gas to the surface, or dissociation rate, or outward diffusion of manganese, which depended on the temperature to form a grain boundary ridge or groove.
关键词:
IF steel
,
oxidation
,
recrystallization
,
grain boundary
高攀，田志红
,
崔阳
,
胡帅
,
李永林
,
朱立新
钢铁
为研究非稳态浇铸对IF钢铸坯洁净的的影响，用钢中气体分析、成分分析、大型夹杂物分析方法对转炉—RH—连铸工艺生产的非稳态浇铸条件下的IF钢铸坯进行取样分析，主要分析头坯、尾坯和换水口坯。结果表明：头坯TO、N、C含量沿拉坯方向呈现上升趋势，Al、Ti正好相反；头坯TO质量分数平均比其他铸坯高0.0015%以上，氮质量分数高达0.0005%以上，碳含量超过判定标准；尾坯、换水口坯TO水平最高分别为正常坯水平的1.6倍和2.2倍，氮含量波动范围分别是正常坯水平的1.0~1.3倍和1.5~1.7倍，碳含量波动范围分别从正常坯水平的1.2~2.4倍和1.2~2.1倍，其他成分波动不大；大型夹杂物含量最高的是头坯34.37mg/(10kg)，其次是尾坯2967mg/(10kg)，然后是换水口坯、大包停浇坯，而正常坯的大型夹杂物含量基本都在1.24mg/(10kg)以下。
关键词:
IF钢
,
unsteady casting
,
slab
,
cleanness
杨吉春
,
杨昌桥
,
周莉
,
王明超
稀土
采用向IF钢中添加微量Ce元素的方法,研究不同Ce含量对IF钢组织和性能的影响.借助于金相显微镜、扫描电镜、能谱仪和万能拉伸试验机等检测手段,对添加Ce的IF钢的显微组织、夹杂物和力学性能进行了表征和分析.结果表明,IF钢中加入微量Ce可明显改善钢的显微组织,晶粒得到细化,且随着Ce含量的增加,分布更加均匀;同时钢中夹杂物得到变性,由原来多边形的A12 O3和TiN复合夹杂转变为椭球状或球状的含Al、Ti的稀土复合夹杂.钢中Ce含量达到0.0042％时,其抗拉强度、屈服强度、延伸率及洛氏硬度比未加Ce的IF钢分别提高了44％、37％、13％和59％.
关键词:
IF钢
,
稀土
,
显微组织
,
力学性能
李镇
,
，王晓峰，林洋，费鹏，姜茂发
钢铁
高纯净度钢的生产是21世纪钢铁企业面临的重大课题，对钢中全氧含量和夹杂物含量的控制是生产高纯净IF钢的关键技术。为此笔者提出一种全新的夹杂物控制技术——反应诱发微小异相去除钢液中细小夹杂物的工艺，设计了一种具有该种功能的复合球体，并开展了工业现场试验研究。试验结果表明：反应诱发微小异相去除细小夹杂物工艺是一种成本低、效率高、简便易行的夹杂物控制技术，它可以显著降低IF钢中非金属夹杂物数量。与传统工艺相比，采用该技术对钢液进行处理后，铸坯中氧化物夹杂的数量明显减少，尺寸变小，铸坯的平均w(［TO］)最低可达7×10-6，吨钢成本可降低5～10元。
关键词:
IF钢
,
composite ball
,
inclusion removal
