韶钢板材抛丸机作业效率提升的改进措施

针对韶钢特轧厂板材抛丸机的使用状况及存在的问题,分析了抛丸器布置不合理、抛丸后钢板表面残留钢丸多、丸料中灰尘杂质较多等导致抛丸机生产效率低下的原因,并提出了相应的改进措施。抛丸机经过改进,作业效率得到有效地提升。     

抛丸机的结构分析及维护

以首钢某常化酸洗机组中的抛丸机为研究对象,介绍了抛丸机的工作原理、设备结构和维护要点。重点对抛丸机的抛丸器和丸粒循环系统进行了结构分析和说明,对抛丸机的设计和维护具有一定的参考价值。     

抛丸机调试解析

以处理冷轧带钢坯的SA1597-0抛丸机结构性能参数为例,详细分析计算,导出了主要调试参数,丸粒在抛头中运动的时间、叶轮转动的角度,丸粒抛射的速度、方向等,再根据对工件(带钢坯)的抛打散射面要求、相关位置及结构尺寸,用作图法确定了抛头定向套定向口的大小,及安装调整位置的方法。据此取得抛丸机成功快速调试,并长期正常生产运行的好结果。对于未能正常生产使用的抛丸机,可供借鉴参考。     

高炉修补压入料的研制

本文简要介绍了高炉修补压入料的特性，采用特级矾土、棕刚玉、致密电熔刚玉和磷酸二氢铝为主要原料，加入适当的辅助原料及添加剂，研制出性能指标优良的压入料。     

宽厚板抛丸机设备维护研究与应用

对宽厚板热处理线抛丸机存在的设备故障、备件成本、能源消耗等问题进行了分析,通过研究和实施设备改造、备件国产化替代等措施,实现了提高抛丸机运行稳定性、降低备件损耗及能源消耗成本的目的。     

抛丸机故障分析及改进

介绍了兴澄特钢热处理线抛丸机的设备结构、参数、技术特点,其装备水平确保了钢板获得最佳的表面质量。同时对现阶段抛丸机在应用实践中出现的吊挂轴承频繁损坏、清扫尾吹装置等故障进行分析并逐一改进和优化。改进后增加了设备的作业率,减少后续工序对设备与生产的影响,降低了备品备件的消耗和人工处理钢板的成本,提高了经济效益,为中厚板厂热处理线抛丸机的应用实践提供借鉴经验。     

提高抛丸机叶片耐用性的途径

分析了轧辊抛丸机叶片失效的原因，指出了提高叶片耐用性的有效途径，在此基础上试制出的叶片，其使用寿命由６天提高到４０天以上。     

中厚板热处理机组抛丸机故障分析与改进

针对中厚板热处理机组抛丸机主要故障进行了分析,提出了相应的设备改进措施.通过更新新箱体、加装高压风装置、调整抛射角度、散化弹丸分离等改进措施后,有效降低了抛丸机故障,满足了热处理生产需求.     

冷轧带钢抛丸机出口漏丸的收集及再利用

通过在抛丸机出口处加装合理设计的钢丸收集机构,抛丸机出口漏钢丸现象导致的钢丸浪费及安全隐患等问题已经得到有效解决,为设备点检和维护创造了良好的条件,满足了清洁生产的管理要求,每年可节省钢丸约50 t。     

提高抛丸机生产效率

抛丸机是酸洗线上的关键设备,它的效率直接影响到整条酸洗线的产量。原设计的抛丸机L1与酸洗线L2的通信方式要求钢板间距约为7 m左右,如果小于7 m会发生钢板信息传输出错。这样的生产节奏过于缓慢,从而严重制约了整条生产线的产能。主要阐述通过改变抛丸机L1与酸洗线L2的通信方式,将钢板间距缩短为2 m左右,从而大大提高了酸洗线的生产能力。目前的生产线产量增长了200%,钢板信息也传输正常。     

Characterization Method of Mechanical Properties of Dissimilar Steel Resistance Plug Welding Joints

A novel resistance plug welding process has wide prospects for dissimilar steel. However, until present, there is no effective method to characterize the mechanical properties of resistance plug welding joints. In this paper, the influence factors such as diameter of filler, diameter of surface plastic ring, and diameter of nugget were first used for analysis. Slug ratio and indentation depth (height) ratio were designed to characterize the mechanical properties of the resistance plug welding joints. The results show that smaller the slug ratio, better the mechanical properties of the joint. The tensile shear load of the joint is higher when the indentation depth (height) ratio is 92–102%, and the joint has the best tensile shear load when the indentation depth (height) ratio is 96% or 97% in this study. Slug ratio and indentation depth (height) ratio are suitable for characterizing mechanical properties of dissimilar steel resistance plug welding joints.     

Finite element simulation of microindentation

Finite element models are created to describe the testing of a material by a Berkovich indenter. The results of calculations by these models are compared to experimental data on indentation of the same material (grade 10 steel). The experimental and calculated data agree well with each other. The developed models for an indenter and the material to be tested are used to find the laws of behavior of a material during indentation. The state of stress in the material under an indenter is studied by various methods. The indentation results are plotted versus the mechanical properties of a material.     

Correlation of microstructure and failure initiating sites in an AISI M2 high-speed steel using Vickers indentation

In this study, the relation of crack initiation and propagation to microstructure was shown in an AISI M2 high-speed steel using Vickers hardness indentation. Observations were carried out on the cracks generated from the corners of the square pyramid indentation in both the as-quenched, the quenched and tempered specimens. It is shown that cracks are nucleated from the corners of the indentation by either cleavage of the carbide or by decohesion between the carbide and the matrix, depending on the size of the carbide. A nucleated crack propagates by tearing of the martensitic matrix between the cracked carbides ahead of the indentation corner. It is shown that the crack resistance of the M2 steel is determined by the toughness of the matrix rather than the size and distribution of the carbides in the matrix.     

2Cr13不锈钢铸坯表面质量的控制研究

2Cr13不锈钢属于包晶钢,其物理特性使得其连铸过程中存在表面凹陷及纵裂纹等质量问题。从该钢种凝固特点、钢的线性膨胀系数以及高温力学性能等方面分析了2Cr13不锈钢铸坯表面凹陷及微裂纹产生的原理并提出了相应的工艺措施,运用于生产实践,降低了2Cr13马氏体不锈连铸坯表面凹陷及裂纹率,保证了产品的表面质量。     

中厚板热处理表面质量缺陷分析与控制

对热处理易出现的丸料压入、钢板下表面炉底辊压痕和钢板边部挤压变形等质量缺陷进行原因分析。通过对抛丸机组改造,在抛丸机上表面增加刮板和吹扫装置,改造下表面抛丸辊道;采用专用的钢板进行洗炉,清理黏附在炉底辊道表面的氧化铁皮;优化装炉制度和工艺参数,制定装炉偏移控制等措施,有效控制热处理钢板的表面质量。钢板热处理质量得到明显改善,提高了产品质量的控制能力。     

耐候钢表面保护性锈层的力学性能

通过连续加载超显微硬度压痕试验测试了耐候钢表面保护性锈层的承载能力.试验结果表明,延长挂片时间,可使耐候钢表面致密锈层开裂的临界压载增大,断裂韧性改善,锈层的承载能力提高,抵抗裂纹扩展的能力增强.     

Substantiation of the ratio of the sample thickness to the indentation depth in hardness measurements

The depths to which plastic deformation occurs under ball indentation of a steel plate at various loads is determined. It is established that the ratio of the depth that plastic deformation reaches to the indentation depth is constant (approximately 15) independently of the indentation load. This finding allows us to conclude that this ratio should be held no less than 15 in hardness measurements. Experiments demonstrate that the lower the hardness of the metal substrate, the larger the decrease in the measured hardness when the ratio is lower than 15.     

不锈钢带连续退火针压缺陷的研究

针压是不锈钢冷轧薄带钢在连续退火酸洗机组生产过程中经常出现的表面缺陷。现场实测及针压缺陷的显微分析结果表明：在连续退火过程中,炉辊与不锈钢带表面存在相对滑动时,辊子表面积累的颗粒状异物是形成针压缺陷的主要原因。为了减少颗粒状异物和改善表面接触状态,现场试验分析发现冷却段3%辊是产生带钢表面针压缺陷的主要部件,改变冷却段3#辊的材质和辊子形状可降低针压缺陷的发生率,采取相应措施使得针压缺陷得到了明显改善。     

Prediction of Indentation Behavior of Superelastic TiNi

Superelastic TiNi shape memory alloys have been extensively used in various applications. The great interest in TiNi alloys is due to its unique shape memory and superelastic effects, along with its superior wear and dent resistance. Assessment of mechanical properties and dent resistance of superelastic TiNi is commonly performed using indentation techniques. However, the coupling of deformation and reversible martensitic transformation of TiNi under indentation conditions makes the interpretation of results challenging. An attempt is made to enhance current interpretation of indentation data. A load-depth curve is predicted that takes into consideration the reversible martensitic transformation. The predicted curve is in good agreement with experimental results. It is found in this study that the elastic modulus is a function of indentation depth. At shallow depths, the elastic modulus is high due to austenite dominance, while at high depths, the elastic modulus drops as the depth increases due to austenite to martensite transition, i.e., martensite dominance. It is also found that TiNi exhibits superior dent resistance compared to AISI 304 steel. There is two orders of magnitude improvement in dent resistance of TiNi in comparison to AISI 304 steel.     

反应等离子喷涂TiN复相涂层的组织与性能研究

采用工业纯钛粉,利用反应等离子喷涂技术,在45钢表面原位合成TiN复相涂层。利用X射线衍射仪分析了涂层的物相组成,采用扫描电镜观察涂层的组织结构、显微压痕、断口和磨损形貌,采用能谱仪分析压痕微区成分,测试了涂层的显微硬度和耐磨性能。结果表明:复相涂层由TiN、TiN0.3、Ti3O组成;涂层具有典型的层状组织结构,且层与层之间、层与基体之间结合较好;涂层的显微硬度为983~1 254 HV0.1;显微压痕形状清晰、规则,且压痕周围无翘边现象;断口形貌说明涂层具有一定的韧性,为介于陶瓷材料与韧性材料之间的混合断裂机制;涂层在低载荷时耐磨性能最佳。