共查询到18条相似文献,搜索用时 68 毫秒
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近年来,国内研究出不少热作模具钢,但是由于供货困难和价格较贵等方面的原因,在气门生产厂家的应用还不很普遍。而3Cr2W8V钢制造的气门模具(图 1),因具有较高的耐热疲劳性和热弹性,所以现阶段用于气成型的模具材料,仍然以3Cr2W8V钢为主。 气门模具的工作条件恶劣,每分钟要经10多次激冷激热的变化,而且承受较大的冲击力。因此要提高3Cr2W8V气门模具的寿命,防止其早期开裂,必须在热处理工艺方面加强探索。 相似文献
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我国电力工业正进入世界先进水平的行列,对锅炉使用的材料,提出了更高的要求,螺栓钢是锅炉装置中阀门及法兰的接合面所用的关键材料之一,本试验对紧固件用钢20CrMo1V1进行了一系列热处理试验,并用扫描电镜和透射电镜对其断口及组织进行了观察,采用电解萃取的方法用X光衍射仪对碳化物进行了确定,从而找出了最佳热处理工艺。 相似文献
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本文介绍了3Cr2W8V气门凹模在生产中经过二次改进的过程和三种不同热处理工艺后模具的性能;阐述了模具在生产中出现的问题及解决办法。 相似文献
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在测试25Cr2Ni2MoV钢核电转子模拟件外圆、内圆、剖面处热处理前后的残余应力分布的基础上,进一步研究了弹性槽对根部打底焊缝处残余应力的影响,测量了盖面焊缝下方4~5层焊道处残余应力的分布。结果表明,弹性槽对缓解根部应力有显著作用,盖面焊缝下方4~5层焊道处存在超过屈服极限的纵向拉应力;热处理后,残余应力大大降低,且保持较好的应力状态。相关测量工作肯定了实际生产工艺对控制残余应力的有效性。 相似文献
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介绍了铝高速钢加工高温合金的切削特点,并对磨损机理进行分析,给出合理的刀具几何参数。 相似文献
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高温氧化对30Cr1Mo1V钢蠕变-疲劳裂纹扩展速率的影响 总被引:1,自引:0,他引:1
在室温、540℃和650℃下,分别研究了空气或氩气气氛中氧化对30Cr1Mo1V钢蠕变-疲劳裂纹扩展速率的影响.结果表明:在高温下,在空气中和加载频率较低时,30Cr1Mo1V钢的裂纹扩展速率均明显增加.在加载过程中引入保载时间,空气中30Cr1Mo1V钢的裂纹扩展速率明显高于惰性环境中,说明氧化影响着疲劳裂纹扩展行为.在惰性气氛中,裂纹扩展速率随保载时间的延长而增大.在空气中,当保载时间超过60 s时,裂纹扩展速率随时间呈线性比例增大,表明此时裂纹扩展行为与时间因素相关. 相似文献
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对30Cr1Mo1V转子钢在540℃和565℃下进行了有中断的蠕变试验研究,应力范围为240-320MPa,得到了蠕变过程中损伤因子和蠕变寿命分数之间的关系。通过蠕变试验后试样维氏硬度的检测和蠕变过程中硬度对蠕变断裂性能的影响分析,提出了蠕变断裂Larson-Miller公式的硬度修正公式,并对其有效性进行了检验。结果表明:在Larson-Miller参数值大于18000时,修正值与实际值比较一致;而在小于该值时相差较大。此外,还研究了损伤和Larson-Miller数之间的关系。 相似文献
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主要针对汽轮机中15Cr1Mo1V锻件管在热处理生产中出现的各种机械不合格现象进行了分析,提出了解决这些问题的具体措施,并应用于生产中,实践这些措施是正确、有效的。 相似文献
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通过室温拉伸、高温拉伸和冲击等试验研究了经过长期服役后的高中压转子30Cr1Mo1V钢不同位置的性能变化,并分析了转子强度和韧性变化的原因.结果表明:转子服役温度高的部位碳化物的形貌、分布和大小均发生变化,贝氏体和铁素体中的碳化物析出、聚集或长大,而原奥氏体晶界和贝氏体与铁素体边界处碳化物析出增多,碳化物颗粒变得粗大;不同位置的拉伸性能差别不大,服役温度最高位置的拉伸强度最低,冲击韧性下降;不同部位总冲击能量的降低主要表现为裂纹形成能的降低,而裂纹扩展能区别很小;高中压转子30Cr1Mo1V钢服役时高温位置的韧脆性转变温度(FATT50)比低温位置明显升高. 相似文献
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Liang Wang XiaoDong Liu Ming Wang WenChuang Liu Xuan Wang FuXin Wang LiangShun Luo YanQing Su JingJie Guo 《International Journal of Hydrogen Energy》2018,43(10):5225-5230
Effects of hydrogen on the interfacial reaction between Ti6Al4V (Ti64) alloy melt and Al2O3 ceramic shell were studied by arc-melting in H2/Ar gaseous mixture. The thickness of interfacial reaction layer between Ti64 alloy melt and Al2O3 ceramic shell without hydrogenation is 80 μm. But the thickness of reaction layer can be reduced to 10 μm at a hydrogen partial pressure of 20 kPa, which is better than the thickness of interface layer between Ti64 alloy and widely used Y2O3 shells. At Ti64 casting surface, the content of β-soft ductile phase is increased and the width of both reaction zone and transition zone are reduced with the increase of hydrogen partial pressure, thus reduces the hardness and the element diffusion distance. Therefore, Hydrogen can effectively control the interfacial reaction in the process of titanium alloy investment casting, and Al2O3 ceramic will be a kind of very promising shell material. 相似文献
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The diffusion bonding of commercially pure titanium and hydrogenated Ti6Al4V alloys was carried out, and the effect of hydrogen was investigated by SEM, XRD, TEM and TG/DSC. The βH phase increased with the hydrogen content increasing in hydrogenated alloys, and the δ titanium hydride and α′ martensite were found in high hydrogen content. The TG curves of hydrogenated alloys descended between 600 °C and 950 °C, and the DSC curves represented a large endothermic peak correspondingly. Moreover, some voids were observed at the diffusion bonding interface. The amount of voids decreased and diffusion bonding quality improved gradually with the increase of hydrogen content, which was attributed to the increase of soft βH phase and release speed of hydrogen as well as the occurrence of more dehydrogenation reaction. 相似文献
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《International Journal of Hydrogen Energy》2023,48(40):15292-15302
The additive manufactured Ti6Al4V-xH titanium alloy was compressed at 600°C–750 °C on a Gleeble 3800 testing machine, and the compression rates were 1s−1 and 0.01s−1, respectively. The experimental results show that with the increase of hydrogen content, the flow stress of the alloy decreases firstly and then increases gradually. When the hydrogen content is 0.27 wt%, the flow stress of titanium alloy is the smallest. EBSD and TEM analysis were carried out and show that the α lamellar microstructure became larger at 0.27H, the corresponding flow stress also decreased, and slip bands appeared in the alloy. Dislocation slip was an important deformation mechanism of the alloy. When the hydrogen content continued to increase, the α phase in the alloy gradually decreased, and α″ appeared at 0.81H. Therefore, adding appropriate hydrogen can reduce the alloy flow stress and improve the performance of titanium alloy during hot deformation. 相似文献