组织细化对中碳Cr-Mo钢力学性能的影响

通过循环热处理和改变奥氏体化温度两种方法获得不同的原奥氏体晶粒尺寸,研究了不同晶粒尺寸对高温回火中碳Cr-Mo钢力学性能的影响.结果表明,当奥氏体化温度低于1 050℃时,实验钢的强度随奥氏体化温度的升高而提高.在相同的奥氏体化温度下,强度随着晶粒的细化而上升.在整个研究范围内,随着晶粒的细化,实验钢的韧性有一定的提高,塑性略有下降.晶粒细化显著提高了钢的低温冲击韧性.     

冲击载荷下低屈服比高强钢板的拉伸性能

通过室温下的仪器化冲击试验和静态拉伸试验,研究一种低屈服比高强度钢板在冲击载荷下的力学性能和断裂机理.结果表明:试验钢的组织由细小岛状马氏体与针状铁素体为主构成,马氏体体积分数为27.6%.与静态拉伸性能相比,在名义应变速率为100 s-1的冲击载荷作用下,试验用钢屈服强度提高31.6%,延伸率不降低.在静态和动态载荷下,该钢均以显微空洞长大聚集的方式发生韧性断裂,但显微空洞的形核和长大方式不同.在静态载荷下,显微空洞形核于颈缩区的铁素体晶粒内部或铁素体-马氏体两相界面处,空洞主要通过两相界面的脱开而形成长大;在动态载荷下,显微空洞主要形核于颈缩区的两相界面处,空洞主要通过马氏体粒子的开裂而形成长大.     

硼对低碳钢中夹杂物形态的影响

研究结果表明:硅锰脱氧的含硼低碳钢中的夹杂物以长条状的MnO-SiO2夹杂物为主,其长宽比为8.7～16.6,变形程度高;随着钢中硼含量的增加,长条状变形夹杂物的比例呈上升的趋势;铝脱氧的低铝含硼低碳钢中的夹杂物以MnO-Al2O3-TiO2与MnS的长条状复合夹杂物为主,其长宽比为9.3～16.3.对比分析认为,这两类长条状夹杂物均为含B2O3的低熔点氧化物塑性夹杂.高铝的含硼低碳钢中的氧化物夹杂主要是Al2O3,未发现变形的长条状氧化物夹杂.     

生产工艺对低碳铝镇静钢热镀锌钢板性能的影响

以在普通热镀锌线生产低碳铝镇静钢深冲热镀锌板为目标,根据CQ、DQ级热镀锌板生产线的工艺特点,设计了以前罩式退火和后罩式退火生产深冲热镀锌板的工艺方案,分别研究了2种工艺对低碳铝镇静钢热镀锌板性能的影响.结果表明:由于低碳铝镇静钢在前罩式退火时会形成强的{111}织构,可以生产性能良好的深冲热镀锌板;后罩式退火也可以改善低碳铝镇静钢热镀锌板的性能,但其冲压性能主要取决于后罩式退火前的各工序.     

超声波作用下不同添加剂对高碳钢凝固组织的影响

 主要研究了在超声波作用下不同添加剂对高碳钢凝固组织的影响。结果表明：在超声波作用下,高碳钢液中添加钛铁、铈可以明显细化其凝固组织,但是添加铝对其凝固组织的细化作用不明显。高碳钢凝固组织的细化是由于Ti（C,N）可以作为非均质形核的核心,促进高碳钢液凝固过程的形核,Ti（C,N）有效的钉扎晶界作用,阻止初生奥氏体晶粒的长大;超声空化作用下稀土氧化物、氧硫化物数量的增多,增加了高碳钢液凝固过程中非均质形核核心的数量。     

低碳钢的表面纳米化组织及其性能

对低碳钢进行表面机械研磨处理(SMAT),研究组织变化及其对性能的影响.结果表明:经过SMAT后,低碳钢上形成了厚度约为40 μm的纳米组织表层,在深度为40～80 μm处获得亚微晶组织;表面纳米化不仅提高了低碳钢表面的硬度和耐磨性,而且在不明显降低韧性的前提下提高了板材的整体强度;在纳米到微米量级的范围内,晶粒尺寸与硬度之间满足Hall-Petch关系.     

低碳锰钢组织性能的小型轧机实验研究

利用包钢技术中心Φ750 mm×550 mm热轧试验机组,研究TMCP工艺参数对w[C]0.06%～w[Mn]1.45%钢组织和力学性能的影响;通过改变TMCP工艺参数,获得了实验钢的多种强度级别及不同组态,为开发各种级别的低成本高强度复相钢提供实验依据。     

电脉冲对高碳钢凝固组织三维碳偏析的影响

通过处理样和空白样的对比研究可知:经电脉冲处理的高碳钢的三维偏析程度明显改善,各横截面上的碳的质量分数波动在4.5%以内,而未处理的碳的质量分数波动达15.1%;不同高度横截面的对应点碳的质量分数分布趋于均匀,中心、1/2半径和边缘各点的碳的质量分数在纵向上波动很小,波动范围在4.5%以内,而未处理的碳的质量分数波动达12.5%。     

爆破不锈钢复合板界面组织和性能分析及应用

研究了普碳钢和不锈钢爆破成型的工艺和组织、性能，结果表明，不锈钢复合板界面呈波纹原子状结合，形成约30μm宽的亚微米级的超细晶粒带，具有高的结合强度，热处理后界面存在碳的扩散，结合区爆破态的硬度高于热处理态。用此工艺生产的不锈钢复合板材料成本低，综合性能好。     

微量钒对高碳钢组织的影响

在“THERMECMASTDR—Z”热加工模拟试验装置上模拟了加热温度、保温时间、变形速度等对含钒高碳钢组织的影响,分析了不同变形温度下氮浓度对析出物的影响。     

电脉冲对高碳钢凝固组织的影响

对处于熔点以上的高碳钢液施加一定时间的电脉冲,观察了不同处理时间后钢样的凝固组织,发现电脉冲能够缩小钢锭的柱状晶区域,减缓柱状晶的生长趋势,提出了一种新的改善钢液凝固过程的技术。在停止电脉冲处理后停留不同时间的情况下,柱状晶的长度不同,电脉冲处理钢液仍然存在衰退问题。此外,还对电脉冲改善金属液凝固组织的机理进行了讨论,不过尚需严格的实验来验证     

Effect of Temper Rolling on Tensile Properties of Low-Si AI-Killed Sheet Steel

The tensile properties of steel after temper rolling are affected by the reduction;low-Si Al-killed sheet steel was taken to study the effect of temper rolling on the tensile properties.The results indicate that the yield strength first decreases with the increase of reduction,and then increases.The relationship between the yield strength and the reduction can be expressed using quadratic function.The tensile strength increases with the increase of the reduction,while the total elongation decreases with the increase of the reduction,and the relationship between them and the reduction can be expressed using power function.Under the same condition,the results also indicate that the yield strength and tensile strength of steels across the rolling direction are all larger than those along the rolling direction; there is no obvious distinction between the total elongation along the rolling direction and that across the rolling direction.     

碳、硅、锰含量对低碳冷拔拉丝钢力学性能的影响

在多年生产冷拔拉丝钢Q195的基础上，成功地开发了低碳冷拔拉丝钢(HL钢)以代替Q195。与Q195相比，该钢伸长率δ10。增加了7．2％，抗拉强度降低了70MPa。介绍了HL钢相关的生产工艺，探讨了钢中碳、硅含量对其力学性能的影响。     

Effect of Temper Rolling on Tensile Properties of Low-Si Al-Killed Sheet Steel

The tensile properties of steel after temper rolling are affected by the reduction; low-Si Al-killed sheet steel was taken to study the effect of temper rolling on the tensile properties. The results indicate that the yield strength first decreases with the increase of reduction, and then increases. The relationship between the yield strength and the reduction can be expressed using quadratic function. The tensile strength increases with the increase of the reduction, while the total elongation decreases with the increase of the reduction, and the relationship between them and the reduction can be expressed using power function. Under the same condition, the results also indicate that the yield strength and tensile strength of steels across the rolling direction are all larger than those along the rolling direction; there is no obvious distinction between the total elongation along the rolling direction and that across the rolling direction.     

Effect of Ultrasonic Treatment on the Solidification Structure of High Carbon Steel Containing Rare Earth Elements

The influence of ultrasonic treatment on solidification structure of high carbon steel with the addition of rare earth Ce was investigated. Effects of various ultrasonic power and treatment time on the solidification structure were studied. The results showed that ultrasonic treatment could obviously refine the solidification structure of high carbon steel containing rare earth Ce. With increasing ultrasonic power, a more refined structure could be obtained. When the ultrasonic power exceeded a certain degree, the effects of ultrasound on structure refinement were not increased significantly. Dendrites developed in the solidifying structure when the ultrasonic treatment times were 0 s and 20 s. However, a uniform and refined dendrite structure was obtained after ultrasonic treatment for 40 s. The solidification structure refinement of high carbon steel containing Ce was ascribed to the increased amount and decreased size of rare earth oxides and oxysulfides by ultrasonic cavitation, which could serve as heterogeneous nuclei of a new crystal phase.     

合金元素钒对高碳钢丝组织与性能的影响

 钒对高碳钢丝的微观组织、力学性能及热稳定性具有显著的影响。钒元素在高碳钢中主要存在于渗碳体中,可以起到强化渗碳体的作用。添加钒元素有利于珠光体片层间距的细化,还可以增加渗碳体的热稳定性,从而抑制钢丝拉拔过程中渗碳体的分解。但在拉拔应变量较大时,富含钒的渗碳体片碎化严重,会加重钢丝在镀锌过程中的球化现象,而导致钒合金化钢丝与未添加钒元素的钢丝相比,无论镀锌与否,其扭转性能均明显下降。     

汽车用冷轧超低碳烘烤硬化钢板的组织性能与析出

实验研究了汽车用冷轧超低碳烘烤硬化钢板的成分、热轧冷轧及退火工艺对钢组织性能的影响规律,并分析了冷轧后连续退火和罩式退火不同条件下钢中析出第2相粒子形态和钢板的织构变化。     

LF炉精炼优质碳素结构钢的生产实践

介绍了新钢公司炼钢厂采用转炉-LF炉-连铸工艺流程生产优质碳素结构钢,采取钢包吹氲及喂丝、LF炉精炼,保护浇铸等有效措施,解决了生产中存在的质量问题与钢水流动性问题。     

高速拉拔低碳钢的表面结构形态、润滑及性能研究

与普线相比,高线拉拔过程中润滑粉吸附不好,影响线材性能。文章研究了控冷工艺、线材表面形态及润滑剂配方对高线低碳钢拉拔过程中润滑粉吸附效果的影响。高线低碳钢拉拔中吐丝温度为930℃时,盘条氧化铁皮中Fe O最厚,润滑粉吸附效果最好,采用延迟冷却,线材表面润滑粉吸附效果好,有利于提高拉丝钢的拉拔性能;轧制吨位在200-600t时,线材的表面状态最有利于润滑粉的吸附;润滑剂中添加30%油性剂,线材表面润滑粉吸附均匀,有利于拉拔过程的润滑。     

Effect of Cyclic Annealing on Microstructure and Mechanical Properties of Medium Carbon Steel

The microstructure and mechanical properties of medium carbon steel after cyclic heat treatment were in-vestigated.The effects of cyclic numbers and long time annealing on the microstructure and mechanical properties of the experimental steel were compared.A short-duration (5 min)holding at 1 023 K (above A1 temperature)and a short-duration (3 min)holding at 893 K are adopted in each cyclic heat treatment.The spheroidization is accelerated during cyclic heat treatment,and the spheroidizing ratio grows with cyclic numbers.After 1 2-cycle heat treatments, there are few incompletely spheroidized regions in the specimens,and cementite lamellae mostly change into cement-ite particles.The morphological character of cementite for 12 cycles is similar to that undergoing annealing for 10 h at 973 K.The strength of the experimental steel after 5-cycle heat treatment is the lowest in the following cyclic heat treatment,but it is still higher than that of specimens with subcritical annealing over a long period (10 h).After 12-cycle heat treatment,the strength of the experimental steel is close to that of the normalized steel,and the plasticity is the best in all heat-treated specimens.