IF钢冷轧薄板的再结晶规律

用差热分析法和硬度法研究了ＩＦ钢在不同加热制度下的再结晶规律，从而为ＩＦ钢实现ＣＡＰＬ连续退火提供了理论依据。     

快速加热时冲压钢的再结晶特点

本文研究了冲压钢冷轧薄板在快速加热条件下的再结晶特点。结果表明．等温加热时治结晶温度随等温时间的延长而降低，连续加热时随着炉温的升高，再结晶过程所需时间缩短，而温度范围变宽。     

600MPa级冷轧双相钢的组织再结晶演变规律

为了指导600MPa级冷轧双相钢后期热处理工艺的制定,利用金相显微技术和硬度测试对冷轧双相钢的组织再结品演变规律作研究。分析再结晶过程对实验钢组织的影响,以及此过程中硬度的变化,建立静态再结晶体积分数模型。实验表明：对于冷轧双相钢而言,再结晶温度一定,随退火时间增加,组织中再结晶的体积分数急剧增加,直至保持在一平台,达到完伞再结品;保温时间一定情况下,随着退火温度的逐渐升高,组织发生再结晶的速度更快;再结晶模型计算值与实测值吻合较好。     

合金化热镀锌IF钢表面条纹缺陷分析

应用金相显微镜、扫描电镜及能谱仪对锌铁合金热镀锌IF钢表面合金化条纹缺陷和对应基板位置的宏观、微观形貌以及缺陷区域化学成分进行分析,发现:合金化热镀锌IF钢表面条纹缺陷区域微观形貌较正常区域平坦;去除表面镀层后,条纹缺陷对应的基板组织存在未完全回复再结晶的轧态组织。与正常回复再结晶组织相比,相同面积下,未完全回复再结晶的轧态组织晶界更少。因IF钢晶界与晶内对应镀层的合金化反应速率不同导致的合金化镀层表面"火山口"数量也更少。不同区域微观形貌的差异导致其对光线的反射效果不同,宏观下呈现为条纹缺陷。     

IF钢冷轧板和冷轧退火板热镀锌层组织和织构的研究

利用金相显微镜和X衍射技术研究了IF钢冷轧板和冷轧退火板热镀锌的不同基材的热镀锌层的组织和织构.结果表明:IF钢冷轧板镀锌层组织为细长的纤维状,织构主要为〈001;〉IF钢冷轧退火板镀锌层组织为均匀等轴状,织构主要为〈011〉.     

CSP冷轧薄板再结晶试验研究

对CSP基板轧制的冷轧薄板试样进行不同温度、时间下的等温退火试验，观察等温退火后试样的硬度变化，研究CSP基板轧制的冷轧薄板在不同压下率下的再结晶动力学特性，确定冷轧压下率对冷轧薄板再结晶动力学的影响。试验结果表明，随冷轧压下率的提高，再结晶温度降低。     

预先再结晶对冷轧双相钢组织性能的影响

通过实验研究了预先再结晶对冷轧双相钢组织性能的影响。首先通过研究再结晶演变规律确定了预先再结晶的温度和时间分别为700℃保温30s;另外,通过奥氏体形成动力学及相变点检测确定两相区退火工艺参数;最后分析了预先再结晶对冷轧双相钢组织性能的影响。实验表明：冷轧钢板经T=700％,t=308预先再结晶处理后,迅速升温进入双相区热处理可以较好的消除了条带状组织,得到均匀的F＋M双相组织,其塑性有了较大幅度的提高,抗拉强度略有上升。     

退火条件对高强度IF钢性能的影响

研究了高强度无间隙原子（ＩＦ）钢的再结晶规律及退火条件对高强ＩＦ钢性能的影响规律，从而找到一套适合现场生产条件的退火工艺参数，为高强ＩＦ钢的生产提供了理论依据。     

Precipitatation Behavior of FeTiP Phase in High Strength IF Steel

The influence of chemical composition and annealing parameters on the behavior of FeTiP precipitation has been investigated. With increasing Ti content the yield strength and tensile strength were reduced, and the tendency of FeTiP precipitation became more remarkable. No FeTiP precipitate was observed and the best mechanical properties have been obtained in the steel sheet, of which the atom ratio of Ti to N is approximately equal to 1. In the temperature range of 700 to 800℃ the FeTiP precipitation could appear easily. The precipitation process was suppressed when the annealing temperature was below 600℃, and the FeTiP phase was dissolved above 900℃. The FeTiP precipitates would inhibit the migration of grain boundaries during the recrystallization in certain extent, and weaken the density of {111} fiber texture, which resulted in the reduction of r value. The relationship between composition and processing parameters, as well as their influence on the mechanical properties is discussed.     

锻造用非调质钢的奥氏体形变再结晶的研究

本文用定量金相方法研究了非调质钢(45MnV)的奥氏体高温形变再结晶行为,目的在于为优化热锻工艺参数寻求基本依据。     

钢临界加热温度回归分析

建立了钢的成分与临界温度之间的关系,分析了回归方程的显著程度．结果表明,相对误差在热处理温度波动范围之内;对制订钢的热处理工艺具有一定的指导作用．     

电炉法生产IF钢的工艺研究

提出了用电炉法生产IF钢的合理工艺配置,阐明了通过采取相应的技术措施如选择合适的炉料配比(增加铁水、DRI或生铁的使用量)、正确的生产操作(如电炉内吹氧喷碳造泡沫渣、钢包内脱氧,注意钢水在连铸过程中的保护浇注等)并配备合适的钢水二次精炼设备如LF+VTD-OB后,可以生产部分IF钢(CQ,DQ和DDQ级)产品.     

IF钢生产过程中的织构演变

对IF钢生产过程中热轧、冷轧及退火试样的织构演变进行研究。分别借助EBSD和XRD测定和计算了热轧、退火及冷轧试样的取向分布函数及相关织构组分的体积分数。结果发现,热轧板在变形过程中发生了动态再结晶,晶粒为细小的等轴晶,为后续组织发展提供了基础;热轧后试样中的织构很弱,不会影响冷轧织构组分及含量。冷轧过程是织构形成的主要过程,试样中含有4种主要的织构组分：{001}〈110〉、{111}〈110〉、{111}〈112〉和{112}〈110〉。退火过程中发生再结晶,4种冷轧织构组分在退火过程中均分别转变为{111}面织构。     

37Mn5钢高温形变再结晶规律的研究

本文采用定量金相的方法研究了37Mn5钢(N80石油套管)在再加热前的不同组织状态、加热温度、形变温度、形变量以及形变后在空气中的停留时间等诸参数对奥氏体高温形变再结晶规律的影响。为钢管在淬火前获得最佳奥氏体状态确定比较合理的工艺参数。     

Clogging behavior of submerged entry nozzles for Ti-bearing IF steel

The nozzle clogging behavior of Ti-bearing IF steel was studied by metallographic analysis,scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).According to the experimental results,nozzle clogging primarily appears three layers.There are a lot of large-sized iron particles in the inner layer and mainly slag phase in the middle and outer layers.The principal clog constituents of the inner layer are loose alumina cluster inclusions and granular shaped alumina i...     

三面受火型钢混凝土柱耐火极限的试验研究与理论分析

制作了2根三面受火型钢混凝土柱,在标准升温条件下进行耐火极限试验,测量了构件轴向变形及中部侧向变形,观察了混凝土的爆裂及构件破坏过程,获得了构件的耐火极限。然后应用有限元软件ABAQUS建立了三面受火型钢混凝土柱三维非线性有限元模型,计算结果得到了试验数据的验证。结果表明,火灾荷载比及偏心率对三面受火型钢混凝土柱的耐火极限有很大的影响,有限元模型可以用来模拟三面受火型钢混凝土柱的温度场及耐火极限。     

Texture evolution of 440 MPa grade Nb-bearing high strength IF steel during rolling and annealing process

The texture evolution from rolling process to annealing process of 440 MPa grade Nb-bearing high strength IF steel (IF-HSS) was studied. Moreover, the texture of different section in thickness direction of steel sheet after annealing was investigated. Macro-texture measurements using XRD shows that hot rolling texture in Nb-bearing IF-HSS includes a weak γ-fiber and α-fiber, of which main texture components are {001}<110>,{111}<110> and {111}<112>. It is worthy of note that the γ-fiber skeleton line formed after hot rolling. During cold rolling, the absolute maximum shifts to {111}<112> along the γ-fiber and the maximum along the α-fiber shifts to {112} <110>. During recrystallization annealing process, the weaker α-fiber and stronger γ-fiber cold rolling texture transformed to a very strong γ-fiber annealing texture. After annealing the main components from surface to mid-section along thickness display the same character for both α-fiber and γ-fiber, while textures intensity at 1/4 section is higher than that of surface and mid-section.