共查询到19条相似文献,搜索用时 171 毫秒
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王仲珏 《中国铸造装备与技术》2005,(2):39-41
采用RE-Ca-Ti-Al对高锰钢进行复合变质.在炉内、炉外实行"二步法"处理并按变质合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态,净化钢液,净化晶界,细化晶粒等良好的变质效果.这些变化主要是复合变质所产生的动力学效应对其影响的结果.这种变质作用受制于复合变质在冶金处理过程中所应具备的相关的动力学条件. 相似文献
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高铬白口铸铁复合变质的作用及动力学效应 总被引:2,自引:0,他引:2
采用Re-A l-B i-Mg对高铬白口铸铁进行复合变质。在炉内、炉外实行"二步法"处理并按变质合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态,净化铁液,净化晶界,细化晶粒等良好的变质效果。这些变化主要是复合变质所产生的动力学效应对其影响的结果。 相似文献
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高铬白口铸铁复合孕育的作用及动力学效应 总被引:1,自引:1,他引:0
王仲珏 《中国铸造装备与技术》2005,(4):51-53
采用V 渣 Ti Zn对高铬白口铸铁进行复合孕育.在炉内、炉外实行"二步法"处理并按孕育合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态,净化铁液,净化晶界,细化晶粒等良好的孕育效果.这些变化主要是复合孕育所产生的动力学效应对其影响的结果. 相似文献
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采用V渣+Ti+Zn对高铬白口铸铁进行复合孕育。在炉内、炉外实行“二步法”处理并按孕育合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态、净化铁液、净化晶界、细化晶粒等良好的孕育效果。 相似文献
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Al-7Si-0.3Mg合金的RE和Sb复合变质 总被引:2,自引:2,他引:0
对Al-7Si-0.3Mg合金进行了Sb和RE复合变质研究.试验结果表明,Sb和RE复合变质可使合金中的共晶硅显著细化,RE加入量增加可使共晶硅出现分枝及向纤维结构转变;差热分析表明,单一Sb和RE变质及Sb、RE复合变质与未变质合金相比,共晶硅析出温度明显降低;以50 ℃/min速度冷却时,0.15%的RE变质合金中共晶硅析出温度比未变质合金低7 ℃,0.15%的Sb 变质合金中共晶硅析出温度比未变质合金低5 ℃,0.15%的Sb 0.15%的RE复合变质时,共晶硅析出温度与0.15%的Sb 变质时接近.Sb促进了共晶硅的形核与细化,RE则促进了共晶硅的分枝与纤维化,复合变质比单一变质(Sb或RE)具有更好的变质效果;Sb和RE复合变质后,合金的力学性能显著提高,特别是伸长率. 相似文献
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《热加工工艺》2017,(7)
研究了La、Pr复合变质对铸造Al-Cu合金的时效硬度、室温力学性能和高温力学性能的影响,并探讨了稀土变质Al-Cu合金的作用机理。结果表明,随着时效温度的升高,未变质和复合变质的Al-Cu合金的峰值硬度都呈现逐渐降低的趋势;在同一时效温度下,Al-Cu合金峰值硬度从高至低顺序依次为:0.2%La+0.1%Pr变质合金0.15%La+0.15%Pr变质合金0.1%La+0.2%Pr变质合金未变质合金;三种不同复合变质Al-Cu合金的室温抗拉强度和断后伸长率都要高于未变质处理的Al-Cu合金,且0.2%La+0.1%Pr复合变质的Al-Cu合金取得了最佳的强度与塑性结合。0.2%La+0.1%Pr复合变质的Al-Cu合金的高温性能优于未变质Al-Cu合金。La和Pr复合变质可以使Al-Cu合金的铸态组织得到有效细化;0.2%La+0.1%Pr复合变质Al-Cu合金在固溶时效处理后,θ'析出相的平均尺寸要比未变质Al-Cu合金小,且数量明显增多。 相似文献
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对比研究了未处理、Zr处理、脉冲磁场处理及脉冲磁场-Zr复合处理对长周期结构增强Mg-5Y-2.5Zn-1.2Ca合金凝固组织及压缩性能的影响,同时考察了复合处理条件下脉冲电压和频率对合金的影响。结果表明,Zr处理、脉冲磁场处理、复合处理后,合金的凝固组织和压缩性能均有所改善,其中复合处理的效果最好;与未处理合金相比,复合处理后合金的抗压强度和压缩率分别提高43.9%和15.4%。在0~300V内,随着脉冲电压增大,合金的平均晶粒尺寸逐渐减小;在1~10Hz内,随着脉冲频率增大,合金的平均晶粒尺寸先减小后增大,转折点为5Hz。晶粒尺寸越小,合金的第二相分布越均匀。合金的压缩性能与其晶粒尺寸基本对应。 相似文献
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Effects of boron and strontium combined treatment on the microstructure of hypoeutectic Al-7Si alloy have been studied.Experimental results show that strontium has no significant effect on the grain refinement efficiency of boron and the eutectic silicon modification efficiency is not only related to the strontium content but also related to the boron content in the Al-7Si alloy melt.There is a negative interaction between boron and strontium that results in the formation of a strontium-boron-aluminum containing compound,which reduces the effective strontium level and decreases the eutectic silicon modification efficiency substantially.The refinement and modification mechanisms remain unchanged after the combined addition of strontium and boron,Based on the experimental results,a model for assessing the modification level in the Al-Si alloy melts after combined addition of boron and strontium was presented. 相似文献
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对白口铸铁采用稀土复合变质处理工艺进行了研究,试验了变质剂的加入量、凝固速度、碳当量、变质温度及时间等工艺因素对改善普通白口铸铁碳化物形貌的影响。结果表明,采用稀土复合变质处理及严格控制工艺因素后,白口铸铁的共晶碳化物由网状分布变成孤立块状分布,有的出现团球状,从而改善了白口铸铁的韧性,使低合金白口铁代替高铬白口铁成为可能。 相似文献
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整体式铝合金轮毂的合金处理及其铸造 总被引:1,自引:0,他引:1
Al-Si系铸造铝合金在铝合金轮毂原铸造中得到了广泛应用。合金的成分控制及其晶粒细化、变质处理等工艺对合金性能影响在。从合金处理,铸造方法等方面对其进行了分析和研究,以期为铝合金轮毂的制造找出合理的途径。 相似文献
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MA Shi-ning HU Chun-hua LI Xin QIU Ji Academy of Armored Force Engineering Beijing China 《材料热处理学报》2004,25(5)
CrMoCu Alloy Cast Iron is a kind of alloy cast iron thatis usually used to manufacture the engine cylinder.The engine cylinder often abates because of scuffingand wear.In order to reduce scuffing and wear,manysteps have been adopted in the practical applications.The first common way is to apply iron nitrating on thewall of the cylinder to form the ion nitride layer.Thehardness of ion nitride layer is so high that the ionnitride layer can improve evidently the wear-resistanceand scuffmg-resis… 相似文献
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纳米改性Cr-Mo-Cu合金铸铁的石墨形态及其性能 总被引:1,自引:1,他引:0
采用X射线衍射仪、扫描电子显微镜及硬度计对纳米改性前后的Cr-Mo-Cu合金铸铁进行了显微组织观察、XRD物相分析和硬度测定,并在生产中考查了由Cr-Mo-Cu合金铸铁制成的光球磨板的磨削加工效率及使用寿命.结果表明,纳米改性后Cr-Mo-Cu合金铸铁中的石墨由形态粗长、数量较少的片状变成了形态细短、数量较多且分散的蠕虫状,晶粒明显细化;XRD衍射峰发生宽化和偏移;洛氏硬度显著提高;制成的Cr-Mo-Cu合金铸铁光球磨板磨削效率和使用寿命均有十分显著的增加. 相似文献
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N. H. Heo 《Metals and Materials International》1996,2(1):49-64
Roles of molybdenum, silicon or aluminum in ferrite on grain boundary segregation and hence on intergranular fracture have been investigated by using Auger electron spectroscopy (AES) and tensile test. Competitive segregation between sulfur and carbon or nitrogen, which caused the decrease below 700°C of sulfur content at the grain boundaries, was observed in the pure iron. The intergranular brittleness of the pure iron was caused by sulfur at the grain boundaries. When molybdenum was added to the pure iron, the sulfur contents at the grain boundaries were lowered in comparison to those in the pure iron. The molybdenum-bearing alloy showed higher fracture strength than that of the pure iron, and fractured mostly in the transgranular mode. This arises from the intrinsic effect of molybdenum on the grain boundaries as well as the decrease in sulfur content. Tn the 3.37 wt.%Si alloy, silicon and carbon or nitrogen competitively segregated to the grain boundaries, and such a competitive segregation was also observed between sulfur and carbon or nitrogen. The sulfur content at the grain boundaries decreased with increasing silicon content. The fracture modes in the 3.37- and 4.26 wt.%Si alloys were transgranular in the rolling direction, but were mostly intergranular in the transverse direction and in the as-rolled condition. The intergranular characteristic in the fracture behavior may be attributed to the detrimental effect of silicon as well as sulfur on the intergranular cohesion. Carbon and aluminum only were found at the grain boundaries of the aluminum-bearing alloy. This suggests that aluminum is a strong repulser of sulfur or nitrogen at the grain boundaries. Additionally, it was found that aluminum has a detrimental effect on grain boundary strength of ferrite. 相似文献
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整体式铝合金轮毂的合金处理及其铸造 总被引:2,自引:1,他引:1
张泉林 《特种铸造及有色合金》2001,(Z1)
Al-Si系铸造铝合金在铝合金轮毂的铸造中应用广泛,合金的成分控制及其晶粒细化、变质处理等工艺对合金性 能影响甚大。从合金处理、铸造方法等角度对其进行了分析和研究,以期为铝合金轮毂的制造提出较合理的途径。 相似文献