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从轧制工艺,省略或简化热处理技术,钢丝变形热处理的等离子加热,控制晶粒长大的热处理技术,新型热处理炉方面,详细地阐述了轧材及钢丝生产技术的最新研究和应用。 相似文献
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钢丝热处理是钢丝生产的重要工序,它不仅影响产品质量,而且也直接关系到能源的消耗,我国目前钢丝单位产品能耗中,用于热处理炉的燃料消耗约占50%,这是由于钢丝热处理的各种窑炉比较落后,热工控制水平不高,炉子热效率较低,例如钢丝生产行业中使用较多的马弗炉,虽然钢丝也是呈展开状态在马弗孔内通过,但由于钢丝与火焰隔绝而被间接加热,以及炉体热损失较大,其热 相似文献
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敞焰无氧化加热的好处是:金属氧化率低,产品质量好,燃料、耐火材料、酸消耗低,炉子产量高,炉子结构简单,改善了工人劳动条件。本文叙述了用于钢丝热处理—酸洗连续作业线中的敞焰无氧化加热炉。×××在钢丝热处理工艺中,长期以来,氧化铁皮是影响产品质量达到某些重要指标的一个严重障碍。而多年来生产中一直沿用的钢丝在耐火砖和陶瓷管马弗炉内加热、然后再进入酸洗 相似文献
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对一种进口钢丝的组织与性能进行了测试,并对其相应的热处理工艺进行了初步的探讨。结果表明,进口钢丝的化学成分与国产35^#中碳钢相近,但它的金相组织非常细小均匀,晶粒大小仅为1~2μm,并且具有良好的强塑性,在拉拔过程中显示出优良的拉拔性能,断丝率较低。可能的热处理方式是仅仅加热到奥氏体和铁素体的两相区进行保温后再冷却至室温,从而呈现出“两相组织”的特殊形貌。 相似文献
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介绍了影响明火加热炉钢丝铅淬火工艺的因素。结合工作实践,总结出在设计铅淬火加热温度和加热时间时,应充分考虑钢丝直径、含碳量和含锰量的影响;随着钢丝直径的增大及含碳量和含锰量的降低,应适当提高钢丝线温;同时随着钢丝直径的增大及含碳量和含锰量的增加,应适当延长加热时间;明火加热炉入口炉温不宜过高,推荐入口炉温比出口炉温增加5%;对于带有铅液循环冷却的铅槽,铅液温度设置要比没有循环装置的铅槽设置的高一些。 相似文献
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为深入理解不同热处理工艺参数对铝硅镀层热成形钢组织性能的影响规律,主要研究了加热温度和保温时间对铝硅镀层热成形钢的硬度、微观组织、镀层厚度和镀层成分的影响。结果表明,当加热温度不大于 900 ℃ 时,铝硅镀层热成形钢的硬度随着保温时间的增加而增加;当加热温度大于 900 ℃ 时,铝硅镀层热成形钢的硬度随着保温时间的增加而下降。当加热温度为850~930 ℃,保温时间为 4、8 min 时铝硅镀层热成形钢的微观组织在模具淬火冷却过程中均转化成为马氏体。在相同加热温度下,铝硅镀层热成形钢合金层的厚度随着保温时间的增加而增大,当加热温度升高至 930 ℃ 时,镀层因氧化而挥发严重,导致镀层变薄,所以铝硅镀层热成形钢的加热温度应控制在 930 ℃ 以下。保温温度升高、保温时间增加导致元素扩散显著,聚集的硅元素含量和面积由于其不断向四周扩散而降低。同时铁元素大量扩散到镀层中,镀层中铁元素含量增加显著。高温下,镀层发生明显的氧化反应,氧化反应促进了微孔洞的形核和长大。 相似文献
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The surface decarburization of hard wire will occur in the process of heating and rolling, which will seriously affect the performance of workpiece. The effects of holding temperature and carbon content on the type and depth of decarburized layer on hard wire 60, 70 and 82B steel were studied by isothermal heating experiment. The effects of crystallite dimensions of original austenite on decarburization depth of spring steel 60Si2MnA were analyzed. The results show that there is only a complete decarburization layer of 60 steel at 700-750℃ after heating at different temperatures for 90min. There is only a partial decarburization layer at 750-850℃. The depth of decarburized layer decreases gradually with the increase of temperature, and there is only a partial decarburization layer at 850-900℃. The depth of complete decarburization layer decreases gradually with the increase of temperature, and the depth of partial decarburization layer increases gradually with the increase of temperature. The partial decarburization layer of 70 steel only exists at 850-900℃. The depth of complete decarburization layer of 82B steel increases gradually with the increase of temperature, then gradually decreases to zero, at least gradually increases. Only a complete decarburization layer exists at 700℃. There is partial decarburization when the hard wires carbon content is in the γ single phase region, and the depth increases with the increase of carbon content. There is complete decarburization when the carbon content is mainly in the α+γ two phase region, and the depth decreases first and then increases with the increase of carbon content. The depth of the complete decarburization layer of the spring steel 60Si2MnA decreases with the increase of crystallite dimensions of original austenite. 相似文献
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摘要:硬线在加热、轧制等过程中会发生表面脱碳,严重影响工件的性能。通过等温加热实验,研究了加热温度和碳含量对硬线60、70和82B钢表面脱碳层类型和深度的影响,及原始奥氏体晶粒尺寸对弹簧钢60Si2MnA表面脱碳类型和深度的影响。结果表明:保温90min后,60钢在700~750℃时仅存在完全脱碳层,在850~900℃时仅存在部分脱碳层,其完全脱碳层深度随温度增加而逐渐减小,部分脱碳层则相反。70钢仅在850~900℃时存在部分脱碳层。82B钢的脱碳层深度随着温度增加先增加后减少至消失,然后又逐渐增加。硬线在碳含量处于γ单相区时主要发生部分脱碳,且深度随碳含量的升高而增大;碳含量处于α+γ两相区时主要发生完全脱碳,且深度随着碳含量增加先减小后增大。弹簧钢60Si2MnA的完全脱碳层深度随着原始奥氏体晶粒尺寸的增大逐渐减小。 相似文献
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BACKGROUND: Alterations in mouth temperature may lead to changes in the force exerted by an activated superelastic wire. It has been assumed that variations in archwire stiffness associated with short-term cooling or heating are transient. This investigation studied the effect of short-term cooling or heating on the bending force exerted by nickel-titanium archwire. MATERIAL AND METHODS: Six rectangular superelastic wires and one conventional nickel-titanium wire were tested in bending at 37 degrees C. The test specimens were deflected 0.5 mm, and the bending force was measured continually. The activated specimens were subjected to cold (10 degrees C) or hot (80 degrees C) water under constant deflection, simulating an inserted archwire that is subjected to cold or hot drinks or food during a meal. RESULTS: The conventional nickel-titanium wire was marginally affected by brief cooling or heating. In contrast, some of the superelastic wires were strongly affected by short-time application of cold or hot water. Whereas the effect of brief heating disappeared quickly, some wires continued to exert sub-baseline bending forces (up to 32% less) after short-time application of cold water and showed little or no tendencies toward increase even after 30 minutes of postexposure restitution (up to 43% less). CONCLUSIONS: Short-term exposures to hot liquid increased the bending force exerted for a given deflection transiently. The effect of short-term exposures to cold liquid was not always transient; the bending force remained sub-baseline for a number of the thermosensitive wires tested for a prolonged time. 相似文献
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研究了二次硬化超高强度AF1410钢(%:0.165C、14.10Co、9.83Ni、1.92Cr、1.05Mo)在800~1200℃ 5~180 min加热的奥氏体晶粒长大行为。结果表明,AF1410钢奥氏体平均晶粒尺寸随加热温度的升高和保温时间延长而增大,加热温度超过1100℃后,奥氏体晶粒发生严重粗化;不同加热温度下,该钢的奥氏体平均晶粒尺寸与保温时间符合Beck关系;建立了AF1410钢的奥氏体晶粒长大数学模型,800~1200℃加热时,该钢奥氏体晶粒长大平均激活能为220.2 kJ/mol,其奥氏体平均晶粒尺寸与加热温度之间符合Arrhenius关系。 相似文献
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本论文阐述的是将各种不同的热喷涂技术与激光表面加工技术进行组合后通过同一个控制系统进行控制的新型集成设备。这种集成设备的优势在于某些工业领域应用部件表面不同部位需要通过两种不同的工艺技术进行处理时,比如沉没辊和发动机叶片。另外,采用激光设备对热喷涂涂层进行后处理并获得更加优异的涂层性能的应用领域也在不断的扩大,比如将热... 相似文献