离合器膜片弹簧的感应回火生产线

介绍了自主研发设计的由感应加热模具、测温系统、控温系统等组成的离合器膜片弹簧感应回火生产线.通过感应加热模具对膜片弹簧进行回火,经过数次生产试验,确定了工艺参数.结果表明,离合器膜片弹簧经双温热模一次性感应加热回火后,中温区回火后的硬度为45～50 HRC,显微组织为回火索氏体;低温区回火后的硬度为55～60 HRC,显微组织为回火马氏体,满足了产品用户要求.     

30CrMnSiNi2A钢零件感应加热局部回火工艺

对30CrMnSiNi2A钢零件进行感应加热局部回火试验,参照铅浴局部回火工艺的相关技术要求,对感应加热热处理的设备、工艺等进行摸索,获得了符合生产要求的感应加热局部回火工艺。试件感应加热局部回火后的疲劳性能和对缺口敏感性的降低都较铅浴局部回火要好。     

模压式感应淬火和回火技术

综合感应加热淬火和压淬工艺的优点,推出了一种新的模压式感应淬火回火技术。该技术的工艺路线是零件感应加热后直接采用模具压力淬火,然后进行原位感应加热回火,这样使得模具的退出很容易而且几乎没有磨损。该技术的主要装备是拥有模压式淬火装置以及感应加热系统的新型淬火机床。它适用于任何高精度圆环形零件的批量生产,如汽车滑套、齿圈、同步圈、伞齿轮、耦件等。     

30CrMnSiNi2A钢螺纹零件局部感应回火工艺

对30CrMnSiNi2A钢螺纹试验件进行了局部感应回火工艺研究，对比研究了不同预处理(等温淬火+低温回火和真空油淬+低温回火)和不同感应回火工艺(单段式加热、两段式加热、两段式加热+移动补温)对工件回火后硬度分布的影响。结果表明，等温淬火+低温回火和真空油淬+低温回火后试验件的硬度和显微组织差别不大。由于集肤效应和端部效应，单段式感应加热会使试验件内部产生较大的径向和轴向硬度梯度，而两段式加热法可通过增设一段均温时间以消除集肤效应所造成的径向硬度梯度，通过感应器移动补温可消除端部效应所导致的轴向硬度梯度。两段式加热+移动补温的感应回火工艺可使试验件螺纹端头的硬度达到要求，并获得均匀的硬度分布。     

钢的感应加热回火

本文对比了改善感应淬硬零件性能的自回火法和感应回火法，同时也评述了感应回火的优点。     

超高强度钢制螺栓的短时回火工艺

讨论采用感应加热的方式对30CrMnSiNi2A钢制螺栓试验件进行局部短时回火处理,分别在700、600和550℃温度下对试样进行保温,保温时间为10 s至50 s,研究了温度和保温时间对试样不同区域硬度的影响,并确定了感应加热的最佳工艺。采用最佳工艺处理了30CrMnSiNi2A钢力学性能试样,测试了其偏斜拉伸和低周疲劳性能,并与铅浴回火工艺进行了比较。研究表明感应加热600℃保温10 s的工艺稳定性最佳,三区硬度分别为:回火区域67~68 HRA;过渡区70~72 HRA;非回火区74~75 HRA,可满足典型制件的技术要求,其处理的偏斜拉伸性能和低周疲劳性能与铅浴工艺处理相当。感应工艺可取代传统有毒的铅浴工艺,用于30CrMnSiNi2A钢制螺栓的生产。     

GCr15钢化纤锭杆高频感应加热局部回火

ＧＣｒ１５钢化纤锭杆高频感应加热局部回火河南省第二纺织机械厂（河南信阳４６４０００）唐质明ＰａｒｔｉａｌＴｅｍｐｅｒｉｎｇｆｏｒＲｏｄｏｆＧＣｒ１５ＳｔｅｌｂｙＨｉｇｈＦｒｅｑｕｅｎｃｙＨｅａｔｉｎｇＴａｎｇＺｈｉｍｉｎ化纤锭杆为细长对称型杆件（见图...     

高频感应加热设备的选用与热处理工艺的制订

高频感应加热设备的选择和热处理工艺的制订主要是根据工件的种类，大小、形状以及硬化层深度等热处理技术要求来选定电流频率、比功率、加热方法、加热功率、加热时间或连续淬火移动速度、冷却介质及冷却参数和回火参数等。     

不同热处理工艺下L245M钢级小弯曲半径感应加热弯管性能的研究

对不同热处理工艺下的L245M钢级小弯曲半径感应加热弯管壁厚分布、力学性能、金相组织进行了检验分析.发现在感应加热弯制后弯曲段管体壁厚发生了明显变化,外弧侧壁厚减薄,内弧侧壁厚增厚.回火处理后,管体壁厚出现回弹;与母管相比,感应加热弯制后弯曲段内弧侧管体强度略有升高,而外弧侧管体强度明显升高,强度增加了近200MPa,...     

摇臂轴感应加热回火工艺的改进

摇臂轴感应加热回火工艺的改进东风汽车公司工艺研究所（十堰市４４２００１）张柏松１前言我公司生产的Ｍ６循环球摇臂轴（以下简称摇臂轴），是汽车转向系统中的零件（图１）。摇臂轴在使用中曾有断裂现象，断裂部位发生在花键与轴杆的过渡处（图２）及轴杆与扇形齿端面...     

硬质合金刺刀座注射成形工艺过程的研究

研究了硬质合金刺刀座注射成形工艺过程。结果表明 :金属注射成形可以生产出性能优良、形状复杂的硬质合金刺刀座 ;MIM工艺生产硬质合金制品与传统的 P/ M法相比 ,制品的尺寸精度较难控制。     

A model to characterize acoustic softening during ultrasonic consolidation

Ultrasonic consolidation (UC) is a solid state bonding process in which thin metal foils are bonded under the influence of ultrasonic vibration and pressure. Large parts can be made by placing foils side by side or by stacking layers to create thicker parts. Thermal and acoustic softening of metals during UC leads to increased plastic deformation and plays an important role in bond formation. In this work, a thermo-mechanical finite element model is developed to quantify the degree of thermal and acoustic softening occurring in Al 1100-0 foils during UC. The model uses experimentally measured temperatures and changes in the foil's geometry during UC to quantify the amount of thermal and acoustic softening. Acoustic softening is shown to reduce the yield stress of Al 1100-0 foils by up to 82%. In addition, thermal softening is found to be relatively minor, typically less than 5% of the total material softening. This method to quantify acoustic softening during UC allows for a better overall understanding of the bonding process and allows several aspects of the UC bonding process to be optimized and improved.     

Hardening and softening processes in iron electrodeposits at friction wear

A method of revealing and estimation of hardening and softening processes in iron electrodeposits at wear process by their sliding friction is proposed. The contribution of hardening and softening processes to wear resistance values can be estimated by the law of variation in values of relative deviations of neighboring units of a statistical ensemble of wear resistance values. It is established that, at the wear process of alloys of iron electrodeposits, the contribution of hardening and softening processes to the wear resistance depends on the alloy composition and test load. At the wear process of composites based on iron with particles of aluminum oxide and with a concentration close to the optimum composition, the contribution of hardening and softening processes is characterized by cyclic recurrence and depends on the load at the interface.     

磷对NiAl合金的软化作用

研究了磷对NiAl合金组织和性能的影响适量的磷能够导致多晶NiAl的软化，即屈服强度和硬度降低以及室温压缩塑性提高。磷固溶于晶格内造成晶内软化，偏聚于晶界造成晶界硬化。磷捕获间隙杂质原子或降低合金的Peierls力是造成晶内软化的原因。合金宏观变形(压缩性能)行为来自晶内软化和晶界硬化的竞争过程。     

X80埋弧焊热影响区的微观组织与局部软化行为分析

以X80高等级管线钢埋弧焊接头作为研究对象,利用小尺寸拉伸样配合数字图像相关技术(DIC)对其热影响区的局部软化现象和失效行为做了表征,研究接头热影响区的强度退化和组织演变之间的关系. 应用数字图像相关技术的拉伸应变云图表明,单道焊热影响区内的一次细晶区(FGHAZ)及两道焊交叠热影响区内的二次细晶亚区(UAFZHAZ和ICFGHAZ)均发生了明显的软化现象. 微观组织表征结果表明,微区内部位错缠结、位错墙等亚结构消失导致的位错强化效果的下降和M/A组元形态及数量变化导致的析出强化效果的减弱是软化发生的主要原因;在两道焊交叠热影响区,二次细晶亚区的局部软化可以被周围的其它区域有效缓和,对接头的安全服役威胁较小,相比之下,一次细晶区的强度退化更值得关注.     

随焊旋转冲击抑制30CrMnSi接头热影响区软化

研究了随焊旋转冲击方法在抑制30CrMnSi接头热影响区软化中的影响规律.?采用随焊旋转冲击装置对焊接过程中产生软化的区域进行旋转冲击,利用维氏硬度计对不同随焊旋转冲击工艺参数作用下的焊接接头热影响区进行硬度测试,通过倒置金相显微镜对常规焊接试样及不同随焊旋转冲击工艺参数作用下的接头软化区进行组织观察,并对软化区C元素...     

Hardness and shear band evolution in bulk metallic glasses after plastic deformation and annealing

Strain-induced hardening and annealing-induced softening are typical in crystalline metals. Bulk metallic glasses (BMG) exhibit the opposite behavior, namely, strain-induced softening and annealing-induced hardening. In addition, reversible softening–hardening–softening occurs in a BMG subjected to a three-step deformation–annealing–deformation process. The hardness changes after deformation and annealing can be correlated with the shear band patterns around/underneath Vickers indents. Shear bands produced during indentation of as-cast BMG are semicircular and radial, consistent with the stress distribution beneath the indenter. In contrast, the shear bands in the pre-strained BMG are irregular and convoluted, and appear to be a mixture of the shear bands produced during the prior compression and those in the as-cast BMG. After annealing, the shear bands tend to recover their semicircular and radial shapes consistent with the annealing-induced hardening.     

海洋平台焊接技术及发展趋势

焊接技术是海洋平台建造的关键工艺。随着深海油气资源的勘探开发,海洋平台用钢向着高强度、大厚度、良好的低温韧性等方向发展,国内海洋平台焊接技术存在自动化水平低、焊接效率低、焊接质量波动大等问题,严重制约着国内海洋工程装备制造的发展。大厚度高强钢的高效焊接技术、高强钢焊接热影响区的脆化和软化、焊接结构的应力与变形控制是现阶段海洋平台焊接亟待解决的问题。窄间隙焊接、激光电弧复合焊、K-TIG、热丝TIG是新型的高效高质量焊接工艺,适用于海洋平台用钢的焊接,可进一步深入研究并在海洋平台建造领域推广应用。     

Mg-8.5Li-3Al-xCe系合金的时效行为研究

采用真空感应熔炼技术制备Mg-8.5Li-3Al-xCe(x=0,1,3)合金。研究Mg-8.5Li-3Al-xCe系合金的时效行为。结果表明,Ce对时效硬化程度具有显著的影响,随Ce含量的增加合金在各时期的硬度都增大,最高时效峰硬度也随之提高,过时效软化的程度随之降低。Ce抑制时效硬化相MgLi2Al和时效软化相AlLi相的生成是Mg-8.5Li-3Al-xCe系合金时效硬化及过时效软化程度降低的主要原因,Ce是抑制Mg-Li-Al合金发生时效软化的有益元素。     

Deposition behavior of thermally softened copper particles in cold spraying

Finite-element analysis (FEA) combined with experimental observation was conducted on preheated Cu particles deposited on Cu substrate to clarify the deposition behavior of thermally softened particles in cold spraying. An explicit FEA code, ABAQUS, was used to predict the deformation features of the thermally softened particles. The experiment was performed by a home-made cold-spray system with a powder preheating device. Considering the possible serious oxidation of the cold-sprayed particles under high-temperature conditions, the preheating temperature was limited to 300 °C for each test. Based on the numerical and experimental results, a new concept called the thermal softening zone within which thermal softening occurs is proposed in the present work. It is found that thermally softened particles deform more intensively compared to non-preheated particles, and a more prominent metal jet can be achieved at the rim of the deformed particles with higher initial temperature. Moreover, the results also reveal that increasing the particle preheating temperature can stimulate the occurrence of thermal softening. For non-preheating or low-temperature preheating particles, thermal softening mainly occurs at the interfacial region. If the preheating temperature is sufficiently high, the whole particle can experience thermal softening. In addition, it is also found that preheated particles are more likely to deposit on the substrate surface than non-preheated particles. In addition, particle preheating is also found to facilitate the coating formation process, enabling the coating to be very thick. The coating microhardness decreases with increasing particle preheating temperature due to the elimination of work hardening by thermal softening.