单晶金刚石刀具钎焊过程研究

对单晶金刚石刀具的钎焊过程进行了研究。指出合理选择单晶金刚石刀具的钎焊方法,严格执行钎焊工艺内容,控制好钎焊过程,可以有效预防或避免钎焊接头处缺陷的产生,有利于获得优质的钎焊接头,延长金刚石刀具的使用寿命。     

液体分配器与分液管的钎焊连接

制冷系统用的液体分配器与分液管接头钎焊方法的选择、钎焊时易出现的问题、正确的钎焊工艺和钎焊注意事项。     

钎焊金刚石工具的研究现状与展望

从钎焊工艺、钎焊料、工具产品和生产自动化4个方面介绍了当前国内外钎焊金刚石工具的研究成果，并在此基础上对钎焊金刚石工具下一步的研究重点进行了展望。详细论述了钎焊温度、保温时间、钎料合金成分对钎焊金刚石的影响。适宜的钎焊温度和保温时间可以保证金刚石/钎料界面发生充分反应，界面结合强度增强，获得较好的钎焊接头质量。添加适量的元素或化合物改进钎料合金成分，可以调控钎料的性能，降低金刚石石墨化和热损伤程度。概括总结了常规钎焊金刚石工具、磨粒有序排布钎焊金刚石工具及细粒度钎焊金刚石工具的发展现状，钎焊金刚石工具具有电镀和烧结金刚石工具无可比拟的优点；金刚石有序排布会提高工具的加工效率和使用寿命，提高磨削表面质量；对细粒度钎焊金刚石工具亟待解决的磨粒等高性和分布均匀性问题的研究进行了概述。     

氮基可控气氛连续纤焊炉成套设备的研制

研制的氮基可控气氛连续钎焊炉,成功地解决了钢质零件的铜钎焊问题。是具有发展前途的新型钎焊设备。     

激光钎焊质量影响因素分析综述

为了提升激光钎焊的连接质量,从激光参数、送丝过程、钎料类型与尺寸等方面分析了影响激光钎焊的各种因素,综述了激光钎焊质量影响因素的研究成果。研究表明,影响激光钎焊质量的因素是综合性的,应通过正交方法做实验,依据统计数据作出分析,从而得到激光钎焊的最佳参数。     

烧结钎焊粉末冶金零件研究

烧结钎焊是一种已确立的粉末冶金零件连接工艺,经常用于生产汽车零部件。成功的钎焊连接主要取决于钎焊合金、连接表面与烧结气氛间的相互作用。将广泛使用的钎焊合金,Ancorbraze 72(AB 72),设计成与焊接的母体材料形成合金和能局部密封钢粉末冶金零件的表面孔隙,从而可防止因熔渗造成钎料材料的大量损失。本文将检验在不同生产工艺条件下钎焊的性状,和研究与表征焊剂与铁使钎焊合金的改性对熔化与凝固性状的影响。     

4004/3003/4004铝合金复合钎焊板包覆率研究

三层铝合金复合钎焊板是制造钎焊式热交换器的重要材料,其中4004/3003/4004是一种使用最为广泛的铝合金复合钎焊板。对4004/3003/4004铝合金复合钎焊板进行热轧复合,分析其包覆层宽度方向分布情况和上下包覆层厚度差异性,并研究不同初始包覆率下轧制后包覆率的变化规律,对实际生产中钎焊板包覆层厚度控制起到重要的指导作用。     

不锈钢/碳钢拉拔钎焊复合管的实验研究

采用拉拔-钎焊的方式制备不锈钢/碳钢复合管,应用金相显微镜观察钎焊后复合界面的微观形貌,实验测试了钎焊温度和保温时间对复合强度的影响。研究发现,钎焊后金属间形成致密的冶金结合,随钎焊温度增加,金属间的剪切强度提高,当温度大于1150℃时,剪切强度从295MPa缓慢增加,随钎焊保温时间剪切强度呈先增大后降低规律。保温3h时剪切强度最大为301MPa。     

感应钎焊工艺对黄铜接头组织的影响

研究了感应钎焊时 ,不同钎焊参数对零件内外表面温度的影响 ,分析了钎焊工艺参数对母材组织和接头质量的影响。缓慢升温可使工件内外表面温度达到平衡 ,钎焊温度在 780℃以下 ,保温时间小于 2 0s的工艺参数可获得优良钎缝和不损伤母材组织。     

热轧4343/3003/7072铝合金钎焊板的组织与性能

采用热轧复合工艺生产4343/3003/7072铝合金钎焊板,利用光学显微镜、电子拉伸试验机和扫描电镜,研究了铝合金钎焊板的包覆率、显微组织和力学性能。结果表明,铝合金钎焊板的包覆层合金厚度均匀、复合界面平整,铝合金钎焊板中4343和7072铝合金包覆层的包覆率分别为9.0%和8.1%,铝合金钎焊板的抗拉强度、屈服强度和伸长率分别为118.62 MPa、56.21 MPa和32.48%。     

新型推链式可控气氛钎焊炉的研制

新型推链式可控气氛钎焊炉,在国内首次采用了在氮基气氛保护下,应用液氮自动喷淋冷却,一次性完成工件钎焊、光亮淬火的新工艺。本文重点介绍了该炉温度控制系统、碳势控制系统及冷却系统     

连续式气体保护钎焊炉的发展现状及其应用

介绍了连续式气体保护钎焊炉的发展现状及其在我国汽车散热器、汽车零部件制造业的应用情况     

冷轧连续热镀锌线退火炉炉内气氛的改善

连续热镀锌生产线的退火炉炉内气氛是由氮气和氢气组成的还原性保护气体,在镀锌线生产中起着还原带钢表面、增加镀锌浸润性的作用,炉内气氛的优劣是决定锌层粘附性的重要因素。重点分析了炉内气氛变差的原因,结合生产实践介绍了退火炉气密性的检查、处理方法以及预防措施,为生产高端汽车板提供优良的炉内气氛保障。     

采用LD-RH-CC工艺生产低碳铝镇静钢技术开发与实践

莱钢炼钢厂为了提高LD-RH-CC工艺生产低碳铝镇静钢技术水平,通过开发全工序低硫冶炼控制技术,构建RH环流模型,开发新型炉渣改质剂,开发连铸机无氧化全保护浇注工艺技术,提高了钢水洁净度,实现了LD-RH-CC工艺稳定控制。其中RH精炼炉终点硫的质量分数控制在0.006%,连铸机浇注炉数达到10炉以上,钢中氮、氧的质量分数达到0.02%以内,稳步推进RH精炼炉冶炼低碳铝镇静钢工艺技术发展。     

40CrB钢冶炼过程中氮含量的控制

以莱钢50 t电炉生产线生产40CrB钢的冶炼过程为对象,分析含硼钢冶炼过程中氮含量的变化情况。结果表明：氮含量呈先降低后增加再降低再增加的变化趋势,整个冶炼过程电炉终点氮含量最低,连铸坯氮含量最高,VD处理有利于降低氮含量;电炉出钢至精炼阶段,氮含量增加最为明显,其次是连铸阶段。通过控制铁水（或生铁）兑入比例、精炼渣量、VD炉操作和保护浇铸,钢中氮含量可以控制在50×10-6以下。     

High Nitrogen Austenitic Stainless Steels Manufactured by Nitrogen Gas Alloying and Adding Nitrided Ferroalloys

 A simple and feasible method for the production of high nitrogen austenitic stainless steels involves nitrogen gas alloying and adding nitrided ferroalloys under normal atmospheric conditions. Alloying by nitrogen gas bubbling in Fe Cr Mn Mo series alloys was carried out in MoSi2 resistance furnace and air induction furnace under normal atmospheric conditions. The results showed that nitrogen alloying could be accelerated by increasing nitrogen gas flow rate, prolonging residence time of bubbles, increasing gas/molten steel interfaces, and decreasing the sulphur and oxygen contents in molten steel. Nitrogen content of 069% in 18Cr18Mn was obtained using air induction furnace by bubbling of nitrogen gas from porous plug. In addition, the nickel free, high nitrogen austenitic stainless steels with sound and compact macrostructure had been produced in the laboratory using vacuum induction furnace and electroslag remelting furnace under nitrogen atmosphere by the addition of nitrided alloy with the maximum nitrogen content of 081%. Pores were observed in the ingots obtained by melting and casting in vacuum induction furnace with the addition of nitrided ferroalloys and under nitrogen atmosphere. After electroslag remelting of the cast ingots, they were all sound and were free of pores. The yield of nitrogen increased with the decrease of melting rate in the ESR process. Due to electroslag remelting under nitrogen atmosphere and the consequential addition of aluminum as deoxidizer to the slag, the loss of manganese decreased obviously. There existed mainly irregular Al2O3 inclusions and MnS inclusions in ESR ingots, and the size of most of the inclusions was less than 5 μm. After homogenization of the hot rolled plate at 1 150 ℃×1 h followed by water quenching, the microstructure consisted of homogeneous austenite.     

国内外加热炉和热处理炉的现状和节能技术

综述了热轧步进梁式炉，薄板坯连铸与连轧之间的加热设备，辊底式炉、连续作业线中的热处理炉和强对流全氢罩式退火炉的现状和节能技术；介绍了蓄热式烧嘴和计算机在轧钢加热炉上的应用。     

Analytical models for the gas carburizing process

Mathematical models for carburizing in batch and continuous furnaces are described. Both the steady-state model for continuous furnaces and the time-dependent model for batch furnaces are based on material balances, with thermodynamic equilibrium of the constituents of the furnace atmosphere assumed. The instantaneous rate of carburizing is taken to be proportional to the difference between the carbon potential of the furnace atmosphere and the surface carbon content of the work load. Computer programs incorporating these models were written which predict furnace operating characteristics for any assumed process. The continuous furnace model predicts the pattern of internal gas flow within the furnace and computes the natural gas (or air) additions to each zone needed to achieve the desired carbon potentials and satisfy the carbon demand. The batch furnace model describes how the furnace atmosphere changes in composition during carburizing as a result of the interaction of the instantaneous carbon demand and the rate of supply of carburizing gases to the furnace. Examples of the use of these programs are given, and the limitations of the predictions are discussed.     

连续退火炉气氛双挡板隔离装置设计分析

高牌号无取向、取向硅钢连续退火炉需要一种隔离炉膛两边气氛的装置。设计这种装置可以实现硅钢二次结晶退火工艺需要的干湿气氛隔离要求,防止相邻炉段的炉膛气氛互相串通,污染炉膛气氛,影响带钢质量。     

高效隧道式节能氮化炉

介绍了连续烧成氮化炉的结构特点、性能及控制方式.连续烧成氮化炉是理想的氮化烧结设备,可以满足大规模连续生产和低能耗的要求,有推广应用的价值.