堆焊药芯焊丝的研制

采用H08A薄钢带作为外皮,研制适用于轧辊等零件修复的药芯焊丝.向焊丝药粉中添加不同含量的Cr,Mo,V,W,B等合金元素,通过硬度试验确定堆焊层耐磨性比较理想的一种配方.采用"多元少量"的原则,加入多种强碳化物形成元素,不但能够提高淬透性,使材料在焊接条件下更快地发生马氏体转变,而且能够形成碳化物、硼化物等细小碳化物硬质相,同时还细化基体晶粒,从而得到硬度与耐磨性较好的堆焊层.试验证明,所研制的药芯焊丝能够满足实践需要.     

Emerging technologies in the hot-dip coating of automotive sheet steel

Customers’ demands for higher-quality hot-dip coated products have led to improved technology for hot-dip coating lines. Because modern hot-dip coating lines operate continuously, the equipment on the line must perform to exacting standards. Current technology in hot-dip lines has transformed the process to the extent that hot-dip products are routinely used for exposed automotive body panel applications. Emerging technologies in hot-dip coating strive to increase the consistency of hot-dip lines and to improve the quality of hot-dip products through a better understanding of the process and implementation of better measurement, control, and production technologies.     

热镀锌DP780钢板成形性能实验研究

对实验室炼制的780 MPa级热镀锌双相钢进行成形性能研究,通过烘烤硬化实验和V形弯曲实验,研究了不同工艺参数对钢板抗凹陷性能和回弹性能的影响。通过扩孔实验深入分析了钢板塑性断裂过程中裂纹的形成与扩展机理。结果表明：小于2%的预应变量可以提高DP780钢的BH值;弯曲变形后实验钢板的回弹角随凸模圆角半径的增大而增大;DP780钢板发生塑性断裂过程中,裂纹通过孔洞相互贯通而形核,并沿着马氏体岛边缘呈“扭折”状进行扩展。     

X70管线钢药芯焊丝CO2焊接

X70管线钢是我国首次生产的微合金化高强钢,并用于西气东输管线。X70作为我国西气东输管线用钢,除了可以采用螺旋焊管埋弧自动焊方法焊接以外,采用药芯焊丝CO2气体保护焊接,也具有良好的焊接性。本研究针对钢桩结构进行了焊接材料与工艺试验。试验试板采用强度等级为60kg级别的药芯焊丝     

A corrosion study of hot-dip galvanized steel sheet pre-treated with γ-mercaptopropyltrimethoxysilane

In the present work an organofunctional silane, γ-mercaptopropyltrimethoxysilane (γ-MPS), has been deposited on hot-dip galvanized cold rolled steel from different silane solution concentrations. Painted and unpainted silane treated samples were corrosion tested and painted samples were adhesion tested. The surface chemistry of the unpainted silane treated samples was investigated with AES, ToF-SIMS and EDS and the surface morphology was studied with SEM.The results show that the silane film thickness is dependent on the silane concentration in the silane solution and a higher silane concentration gives a thicker film. Moreover, thicker films tend to give films with a pronounced crack pattern and even detachment of film debris. Corrosion tests of unpainted samples show that γ-MPS can not work as a passivation treatment but gives a very good adhesion to the paint.     

连续退火热镀锌板镀层表面黑点缺陷研究

研究了热镀锌板镀层表面黑点的产生机理,分析了该缺陷对热镀锌板涂镀质量的影响,提出了相应的改进措施。结果表明,基板表面存在微小凹坑,镀锌后表面形成黑色圆形氧化膜,即黑点缺陷,对热镀锌板涂镀后的磷化膜质量产生不利影响。实际生产中,通过降低热轧卷的卷曲温度、清洗槽电解电流密度及提高退火炉的密封性,可有效减轻该缺陷。     

碳化钨条填充法电弧堆焊工艺及堆焊层泥沙磨损研究

介绍 了铸造碳化钨条填充法电弧堆焊制备金属基碳化钨陶瓷复合材料耐磨层的基本过程，叙述了该方法堆焊工艺特点及电弧烧作用对碳化钨颗粒形状及性能的影响，结合堆焊工艺论述了复合材料堆焊层的成分和性能特点。对铸造碳化钨条填充法电弧堆焊制备的复合材料堆焊层进行了泥沙磨损试验，并将其耐磨性与焊条熔敷金属的耐磨性进行了对比。讨论分析了作为硬质相的碳化钨颗粒的基体对堆焊层抗泥沙磨损性能的影响。     

激光介入不锈钢自保护药芯焊丝MAG电弧堆焊熔滴受力分析

以不锈钢自保护药芯焊丝为研究对象,借助高速摄像采集了激光介入MAG电弧堆焊的熔滴和电弧图像,研究了激光介入不锈钢自保护药芯焊丝MAG电弧堆焊的熔滴受力. 结果表明,激光的介入改变了焊丝端头熔化状态,焊丝端头发生局部熔化、半熔熔化、全熔熔化三种状态;增大了电磁收缩力、等离子流力在焊丝轴线上的分力,有利于熔滴过渡;减小了表面张力,有利于细化熔滴;增加了气体动力,在合适的激光参数下促进熔滴过渡;熔滴过渡轨迹出现了右偏轴过渡、左偏轴过渡、沿轴过渡三种模式.     

A two-step roll coating phosphate/molybdate passivation treatment for hot-dip galvanized steel sheet

A two-step roll coating passivation treatment employing phosphate followed by molybdate solutions has been performed on hot-dip galvanized (GI) steel sheet. The phosphate coating was primarily porous, amorphous Zn phosphate. A second step coating treatment resulted in more hemispherical Zn phosphate particles and the incorporation of molybdate ions and molybdenum oxide into the existing phosphate coating, giving rise to an improved corrosion resistance. The coating reaction during the second step roll coating treatment and the corrosion protection afforded by the second step molybdate treatment are discussed, with emphases on the comparison with the coating formed via immersion.     

时效硬化工具合金TIG堆焊金属粉芯焊丝热处理工艺研究

通过研究时效硬化工具合金TIG堆焊金属粉芯焊丝堆焊层金属的热处理工艺及其显微组织，分析了堆焊层金属强化的机理。研究表明，固溶处理和时效处理对所研制焊丝的堆焊硬度有着显著的.了终确定的固溶－时效热处理工艺为：（1）1260℃保温6min后水冷淬火，然后进行560℃保温2h的时效处理；（2）最终确定的焊后直接时效处理的工艺为560℃保温2.5h。     

用H08A盘条轧制药芯焊丝

我公司与东北大学于 1992年联合进行了用6.5ｍｍ的Ｈ0 8Ａ盘条作原料轧制药芯焊丝的研究工作 ,1993年轧制药芯焊丝设备在我公司安装并调试。药芯焊丝的生产在国内有很多家 ,但都使用带钢生产药芯焊丝 ,用盘条轧制药芯焊丝的优势在于盘条比带钢成本低 ,轧出的焊丝挺度好 ,但也有不利的一面 ,在设备方面增加了开槽机组 ,在生产过程中轧辊、轴承易损 ,增大了生产费用 ,生产效率相对低于用带钢轧制药芯焊丝设备 ,生产工艺比用带钢生产复杂。从药芯焊丝的生产方面看 ,加工难度远远大于用带钢轧制。例如 :经过开槽后轧制出的异型带钢产生了加工…     

Corrosion behavior and resistance of hot-dip Al−Cr coated steel sheet under a salt corrosive environment

The corrosion behavior and resistance of hot-dip Al and Al−Cr coated steel sheets (SS) were investigated via scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), electron probe micro analysis (EPMA), glow discharge light spectroscopy (GDLS), and X-ray diffraction patterns (XRD). The Al−Cr coated layer was composed of the following three phases. Al phase comprised the surface layer, Al₁₃Cr₂ the middle layer, and Al₁₃Fe₄ and Al₅Fe₂ phases the interfacial layer between the Fe substrate and the coated layer. The corrosion behavior of the Al−Cr coated layer showed different aspects compared with the Al coated layer. In the Al−Cr coated layer, Cr was observed at an intermediate layer having a band shape. From the analysis of the polarization curve, the initial corrosion current of the Al−Cr coated SS was 10 times lower than that of Al in the early stage, and the corrosion resistance was superior to that of Al. The Al coated SS formed an Al−Fe−Si IMC layer, and the coated layer was almost destroyed. Many cracks were produced, and the corroded parts were enlarged from the cracks. The upper part of the Al−Cr coated SS, an Al−Si coated layer, was corroded. In contrast, the Cr-rich intermediate layer was not destroyed. Consequently, the high corrosion resistance was attributed to the densely covered Al(OH)₃ and the intermetallic compound layer of Al₁₃Cr₂. These results significantly contribute toward attaining a detailed understanding of the corrosion behavior and resistance Al−Cr coated steel sheets.     

Effect of Mg2+ on the microstructure and corrosion resistance of the phosphate conversion coating on hot-dip galvanized sheet steel

The effect of Mg²⁺ in the phosphate solution on the microstructural evolution and corrosion resistance of the coating on hot-dip galvanized steel has been explored. Surface morphology observations reveal that increasing the solution Mg²⁺ concentration increases the population density and refines the grain size of the phosphate grains. In the presence of Mg²⁺, the phosphate coating is composed of mixed Zn phosphate hydrate and (Zn, Mg) phosphate hydrate. Furthermore, elevating Mg²⁺ in the solution reduces the porosity of the phosphate coating. As a result, the corrosion resistance of the phosphate coating is improved.     

磷化处理对无铬钝化热镀锌板耐蚀性能的影响

研究了磷化处理工艺对无铬钝化热镀锌板耐腐蚀性能和表面形貌的影响。采用扫描电镜对其表面形貌进行分析，同时与未经过磷化处理的钝化板表面形貌进行对比；采用电化学阳极极化曲线方法和电化学阻抗法对磷化处理后钝化板的耐腐蚀性能进行了研究。在钝化板膜重为0.8 g/m²的情况下，经磷化处理的钝化板表面钝化膜完好，没有发现锈蚀或钝化膜剥落现象；经磷化处理的钝化板自腐蚀电位和阳极电流密度不变，阴极电流密度和自腐蚀电流密度有所提高；Nyquist图的高频部分在磷化处理前为容抗弧，磷化处理后出现具有Warburg阻抗的直线，说明磷化处理后钝化膜表面出现扩散过程。 研究表明，钝化板经过磷化处理后表面未形成磷化膜，耐腐蚀性能仍来自原钝化膜，经磷化处理的钝化板的耐腐蚀性能有所降低。因此，现有常规的磷化处理并没有增加钝化板的耐腐蚀性能，如果有需要提高钝化板耐腐蚀性能的要求，必须针对无铬钝化板研制专用的磷化液和磷化工艺。     

氮合金化药芯焊丝对堆焊层组织和耐磨性的影响

在Cr13马氏体不锈钢药芯焊丝中添加2%铌铁、2%钒铁和5%氮化铬进行埋弧堆焊,研究氮合金化对堆焊层组织和耐磨性的影响。堆焊层试样分别在450℃、480℃、500℃、520℃、540℃、560℃和600℃下进行焊后回火处理,研究回火温度对堆焊层组织和耐磨性的影响。结果表明,焊态下硬面合金组织由马氏体、残余奥氏体和分布在基体上的碳氮化物组成。加入铌、钒和氮化铬后,组织的晶粒得到细化,耐磨性也随之提高。回火热处理使基体晶内及晶界弥散析出球状第二相粒子(Nb、V、Cr)x(C、N)y,随着回火温度的升高,氮合金化硬面合金中第二相粒子的数量先略有下降,再逐渐增加,随后急剧减少,耐磨性也相应改变。540℃时试样磨损量最小,耐磨性最佳,当回火温度升至600℃时,第二相粒子数量减少,耐磨性最差。     

扩散型热浸镀铝-镧钢的抗腐蚀机理研究

对扩散型热浸镀铝-镧钢的抗H2S腐蚀性能及机理进行了研究.通过SEM、TEM、XRD等对热浸镀铝-镧扩散层的组织结构进行观察和分析.结果表明,稀土镧可提高热浸镀铝钢的抗腐蚀性能.热浸镀铝-镧钢的扩散层中存在非晶态相,且稀土镧的添加可使扩散层中的非晶含量增加.在靠近扩散层的最外层表面有一约30 μm厚的过渡层,该层为非晶态占优的非晶合金与纳米晶粒的混合区,且随着深度增加,非晶逐渐减少.分析认为,扩散层中存在大量的非晶态合金是稀土镧提高扩散型热浸镀铝钢抗腐蚀性能的主要原因.     

热轧钢带连续热镀锌

介绍了热轧钢带连续热镀锌的背景、工艺和设备 ,并列出了宽、窄钢带热镀锌生产线的实例。     

有花热基镀锌板锌花均匀性研究及其工业化控制

针对国内某大型改良森吉米尔法热基镀锌产线生产的有花热基镀锌板锌花尺寸不均的问题,采用电子探针、激光共聚焦及定容法等试验手段,系统研究了带钢不同位置的元素分布特点和酸洗时间对锌花尺寸的影响规律。结果表明:带钢厚度、表面粗糙度、镀层元素分布等因素均会对锌花均匀性产生显著影响;优化带钢在热轧时的厚度控制模型、缩小带钢在酸洗时的产线速度差、提高锌液中Sb的含量以及增加镀锌后冷却装置均可以有效提高锌花均匀性。在实际生产中,通过优化热轧、酸洗、镀锌等工艺,热基镀锌产品带头(尾)、带中锌花不均质量缺陷发生率由之前的21%~32%降至了3%~10%。     

钢带热镀锌技术研究进展

综述了钢带连续热镀锌技术研究的进展,包括工艺的优化和改进、高耐蚀性镀层的开发、高强钢带热镀锌以及镀层性能的研究进展等,讨论了现在和将来一段时间内热镀锌工艺技术研究的重点,并指出我国在合金化工艺、后处理工艺和高强钢可镀性等方面的研究应进一步加强.     

浸镀温度对热镀Galfan钢丝镀层的影响

在不同浸镀温度下制备了钢丝热浸镀Galfan镀层,运用扫描电镜、x射线衍射仪、X射线光电子能谱仪、电化学工作站研究了浸镀温度对钢丝还原法热镀Galfan(Zn-5%Al-RE合金)镀层厚度和组织的影响.结果表明,镀层界面层厚度随还原温度呈波浪形变化,在445℃处存在峰值;界面层主要由Fe_2Al_2FeAl_3组成,415-4359C镀层界面层中存在微量Al_20_3;极化曲线分析表明,界面层存在扫描电镜下无法观察到的分层.