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介绍了用0.2%—0.4%Cr灰铁代替HT200生产汽车制动鼓的生产技术,分析了铁液化学成份和生产要点。该方法提高了铸件的强度、硬度、耐磨性和切削加工性能,铸造性能也得到改善。实践表明,该生产方法大大降低了废品率,经济效益显著。 相似文献
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AbstractThe microsegregation of Mn, Cu, Cr, Mo, Ni and Si has been measured in ductile iron which has been quenched during solidification. Effective segregation coefficients have been determined for each of the elements, and used to calculate the segregation on the basis of the Scheil equation. The calculated values agree reasonably well with the measured values of solute concentration as a function of the solid fraction. On the basis of the measured segregation of the alloying elements, the mechanisms by which the segregation affects the as-cast microstructure are considered, and an explanation for the effect of the segregation on the hardenability of ductile iron is proposed. 相似文献
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M. W. Shin G. H. Jang J. K. Kim H. Y. Kim Ho Jang 《Journal of Materials Engineering and Performance》2013,22(4):1129-1135
Thermal distortion of gray iron brake disks due to residual stress and its effect on brake vibrations were studied. The residual stress of heat- and non-heat-treated gray iron disks was measured using neutron scattering. Dynamometer tests were performed to measure the friction force oscillation caused by the disk runout during brake applications. High-temperature tensile tests were carried out to find out possible plastic deformation due to residual stress during brake applications. The results showed that the average residual stress of the heat-treated disk (47.6 MPa) was lower than that of the non-heat-treated disk (99.6 MPa). Dynamometer tests at high temperatures (up to 600 °C) indicated that the residual stress pronounced the runout: the increase in disk runout after the tests for the non-heat-treated sample was more than twice that for the heat-treated sample. This difference correlated well with the neutron scattering results and the dimensional changes after a separate vacuum heat treatment. The high-temperature tensile tests showed severe reductions in yield strength at 600 °C, suggesting that disks produced with no stress relaxation could be deformed during severe braking. 相似文献
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对比了在相同的孕育剂75SiFe孕育下多元合金添加剂(RE、Cr、Mn、Si、Fe)和Cu分别合金化处理得到的灰铸铁力学性能和加工性能,以及多元合金添加剂合金化处理不同孕育剂孕育得到的灰铸铁力学性能和加工性能.结果表明:在75SiFe孕育的情况下,多元合金添加剂合金化处理的灰铸铁与Cu合金化处理的灰铸铁相比,抗拉强度降低了6.5%,主切削力降低了3.5%~7.7%(切削深度2~3 mm),加工性能略好.均用多元合金添加剂合金化处理时,使用不同孕育剂75SiFe、SrSi和BaSi孕育得到的灰铸铁件强度基本相同,而SrSi孕育处理的灰铸铁切削加工性能最好. 相似文献
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研究了添加Cr、Ni、Mo合金元素的球墨铸铁,分别以90°和45°冲击角度在酸性、中性和碱性石英砂介质中的冲蚀腐蚀磨损特性。结果表明:球墨铸铁的冲蚀腐蚀磨损耐磨性随合金元素的加入而增加,并且随介质pH值和冲击角度的增加而增加。球墨铸铁冲蚀腐蚀磨损的机理,在酸性介质中是以粒子显微切削和腐蚀共同作用为主,而在中性和碱性介质中是以粒子显微切削为主,腐蚀的作用很弱。 相似文献
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高碳当量高强度低铬铜合金灰铸铁的试验研究 总被引:5,自引:0,他引:5
针对高碳当量灰铸铁,试验了少量合金元素Cr、Cu对抗拉强度及白口倾向的影响。结果表明:合金元素Cr和Cu对灰铸铁的强度有明显的影响,在碳当量为3.9% ̄4.1%的条件下,铁水中合金元素Cr和Cu的合理含量分别为:0.20% ̄0.25%以及0.40% ̄0.45%。此外,初步分析了合金元素Cr和Cu对灰铸铁强度及组织的影响机理。 相似文献
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介绍了采用不同配比的废旧轮胎内钢丝和回炉料作为主要原材料,使用增碳剂进行增碳,使用75硅铁孕育剂和硅钡钙铝长效孕育剂进行随流孕育,并加入Cr、Cu等合金元素进行组织强化。在相同铸造工艺下,制备化学成分基本相同的灰铸铁制动盘和准30 mm的单铸试棒,然后对试件的金相组织、硬度、抗拉强度进行检测分析。结果表明,不同的原材料配比对金相组织中的石墨的类型、长度以及珠光体的片间距有着较大的影响,珠光体含量未发生明显变化;对硬度和抗拉强度影响较大,当废旧轮胎内钢丝的加入比例由70%变为80%时,抗拉强度与硬度变化明显。随着废旧轮胎内钢丝的比例不断增加,A型石墨的比例不断升高,由93.7%增长至99.2%;珠光体含量由95.3%增长至99.1%,珠光体石墨与珠光体逐渐细化,抗拉强度及硬度逐渐升高,满足了高性能制动盘的性能要求。 相似文献
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介绍了常用灰铸铁制动鼓铸件的产品要求,采用铁型覆砂铸造生产灰铸铁制动鼓的工艺和生产实践,中的控制条件和注意事项. 相似文献
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由于炉料成分和熔炼条件的波动,使得热分析法在铸铁炉前成分检测精度上出现不稳定的情况.本文分别采用加碲和不加碲的样杯对灰铸铁进行热分析试验,通过二元线性回归建立热分析数学模型,比较成分检测的精度.研究结果表明,对于生产中炉料变化不大的情况,采用不加碲样杯进行热分析测试的精度会更高;如果不能严格控制炉料,用加碲样杯进行热分析,则能够保证比较稳定的精度.针对不同的炉料和熔炼条件,选用合适的热分析数学模型,是铸铁炉前质量控制成功与否的关键. 相似文献
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在CE为4.4%~4.5%的高导热铸铁制动盘中加入不同量的铌合金,研究了Nb对其组织和力学性能的影响。结果表明,CE为4.4%、w(Nb)量为0.09%时,高导热铸铁制动盘石墨组织细化,力学性能得到一定的提高,磨损量降低,制动盘的抗热裂性提高。 相似文献