亚共晶高铬铸铁二次加热组织演变及触变挤压充型性能研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
本文采用倾斜板冷却体法制备亚共晶高铬铸铁半固态坯料,并对半固态坯料进行二次加热,然后进行触变挤压充型。考察了保温时间和重熔温度对坯料在二次加热过程中组织演变的影响规律。研究了保温时间和重熔温度对坯料充型性能的影响,充型件的质量、组织,并对充型件力学性能进行了初步分析。
     半固态坯料在半固态区域保温过程中,先共晶奥氏体晶粒经历了由球化到合并长大的循环演变过程,且保温前期循环时间要短于后期,保温后期晶粒形貌恶化程度较前期严重。随着重熔温度的升高,奥氏体晶粒球化和合并长大的速度由快转慢,晶粒恶化程度逐渐变小。当重熔温度过高时,晶粒粗化严重,试样氧化严重,并发生流淌现象。
     铸态试样组织为发达的枝晶网络结构,当重熔温度较低时,即使延长保温时间,枝晶组织也难以球化。提高重熔温度及延长保温时间,枝晶组织才能够发生熔断,并开始球化,但球化效果不理想,且晶粒粗化严重。
     半固态坯料较铸态坯料具有较好的充型性能,铸态坯料难以充型。当重熔温度较低时,半固态坯料难以完全充型;提高重熔温度,当保温时间较短时,坯料难以充满整个模具型腔;延长保温时间,坯料能够充满整个型腔,且充型件表面质量较好。当重熔温度过高时,坯料充型性能很好,但充型件表面质量较差。
     流变充型件内部质量不致密,充型件中部存在较多的集中缩孔;触变充型件内部质量较好,但有些工艺参数下的试样上部存在一些裂纹和缩松。
     触变充型过程中,晶粒被压碎,使得晶粒较充型前得到显著细化。试样轴向由上部到下部,晶粒尺寸不断减小,其中上部存在大量粗枝晶,中部晶粒圆整度较高,且大小分布均匀。试样横向从边部到中部,晶粒略有长大,但变化不明显。随着保温时间的延长,充型件组织中的晶粒尺寸有所增大。
     触变充型件较致密,且充型件组织细小,较流变充型件具有较高的力学性能。
Semi-solid billets of hypoeutectic high chromium cast iron prepared by inclined cooling plate method were reheated, then thixotropic extruding filled. The influences of holding time and reheating temperature on microstructure of semi-solid billets and as-cast billets during reheating were investigated. The influences of holding time and reheating temperature on the filling property and microstructure and mechanical property of filled parts were studied.
     Semi-solid billets during the semi-solid interval, pro-eutectic austenite grains circulated from the spheroidizing to the merge growing process, and the cycle time was prolonged gradually, and the final period of exacerbation was more prominent than prior period. With the reheating temperature up, the speed of the spheroidizing and the merge growing of grains changed from quick to slow, and exacerbation changed small gradually. When the reheating temperature is enough excessive, the coarsing of grains was serious, and sample oxidized serious and flowed.
     As-cast billets possess dendritic structure, when the reheating temperature was lower, even if prolonged the holding time, the dendritic structure was also hard to spheroidized. Increasing the reheating temperature and prolonging the holding time, the dendritic structure just began to burn out and spheroidized, but the spheroidized effect was not ideal, meanwhile the coarsing of grains was serious.
     Semi-solid billets have better filling property than as-cast billets, and as-cast billets are difficult to filling. When the reheating temperature is low, billets can not filling wholly. Increasing the reheating temperature, when the holding time is short, and billets are difficult to filling wholly. Prolonging the holding time, reheating of billets is more homogeneous, billets can filled wholly with better surface quality. When the reheating temperature is too higher, although billets can filling wholly, the surface quality of filling parts is lower.
     The internal soundness of rheologic filled parts is unsound, and has much central shrinkage cavity in the middle of filled parts. The thixotropic filled parts have better internal soundness, but some filled parts have shrinkage porosity and crack upside the parts.
     The microstructure of thixotropic filled parts has much refinement than before filled parts, because grains were crushed. Axial direction of parts from top to down, the size of grains become fine gradually, and the grains in the upper position of sample has much dendritic, and the roundness of grains in the middle of parts was high, and grains distributed evenly. Cross direction of parts from margin to center, grains grow in some sort, but the change was not obvious. Prolonging the holding time, the microstructure of filled parts was a little increase.
     The thixotropic filled parts have high mechanical property than rheologic filled parts, and filled parts have higher density and fine grains.
引文
[1]Flemings M C.Behavior of metal alloys in the semisolid state.Metal Transactions,1991,22 A(5):957-981
    [2]康永林,毛卫民,胡壮麒.金属半固态加工理论与技术.北京:科学出版社,2004
    [3]周尧和,胡壮麒,介万奇.凝固技术.北京:机械工业出版社,1998
    [4]谢水生,黄声宏.半固态金属加工技术及其应用.北京:冶金工业出版社,1999
    [5]朱鸣芳,苏华钦.半固态铸造技术的研究现状.特种铸造及有色合金,1996,(2):29-32
    [6]毛卫民.半固态金属成形技术.北京:机械工业出版社,2004
    [7]管仁国,马伟民.金属半固态成形理论与技术.北京:冶金工业出版社,2005
    [8]陈嵩生.半固态铸造.北京:国防工业出版社,1978
    [9]冯鹏发,曾大本,唐靖林,等.半固态合金流变成形技术的研究现状与发展.铸造,2004,53(12):963-967
    [10]Kang C G.The upsetting Behavior of Semi-solid Aluminum Material Fabricated by a Mechanical Stirring Process.Journal of Materials Processing Technology,1997,66(1-3):30-38
    [11]刘昌明,何乃军.过共晶铝硅合金半固态挤压铸造近终成形技术研究.金属成形工艺,2001,(1):38-41
    [12]Brown S B,Flemings M C.Net-Shape Forming via Semi-Solid Processing.Advanced Materials Processes,1993,143(1):36-40
    [13]Motegi T.Continuous casting of semisolid A1-Si-Mg alloy.Processing of the ICAA-6,(1998),297-236
    [14]夏明许.SIMA法制备半固态镁合金的研究:[硕士学位论文].西安:西安理工大学,2003
    [15]陈体军,郝远.预变形SiCp/ZA27复合材料在半固态等温热处理过程中组织的扫描电镜观察.铸造,2003,52(3):180-184
    [16]Young K P,Kynoka C P.Fine Grained Metal Composition.US Patent,4415374,1983
    [17]Lou S J,Tian W T.Structure evolution of LC4 alloy in making thixotropic billet by SIMA method.Transactions Nonferrous Metals Society of China,2001,11(8):547-550
    [18]刘昌明,邹茂华,章宗和,等.形变诱导法半固态加热工艺参数对LY12组织和晶粒尺寸的影响.中国有色金属学报,2002,12(3):436-441
    [19]H.Q.Lin,J.G.Wang,H.Y.Wang,et al.Effect of predeformation on the globular grains in AZ91D alloy during strain induced melt activation(SIMA)process.Journal of Alloys and compounds,2007,431:141-147
    [20]李元东,郝远,陈体军,等.等温热处理工艺对AZ91D镁合金半固态组织演变和成形性的影响.中国有色金属学报,2002,12(6):1143-1147
    [21]李元东,郝远,陈体军,等.原始组织对半固态AZ91D镁合金重熔行为的影响.中国有色金属学报,2004,14(3):366-371
    [22]李元东,郝远,闫峰云.AZ91D镁合金在半固态等温热处理中的组织演变.中国有色金属学报,2001,11(4):571-575
    [23]Apelian D.Semi-solid processing routes and microstructure evolution.In:Tsutsui Y,Kiuchi M and Ichikawa K.Proc.of the 7th Int.Conf.on Semi-Solid Processing of Alloys and Composites,Tsukuba,Japan,Sept 25th-27th,2002,National Institute of Advanced Industrial Science and Technology,Japan Society for Technology of Plasticity:25-30
    [24]董杰,路贵民,任栖锋,等.液相线铸造法非枝晶半固态组织形成机理探讨.合金学报,2002,38(2):203-207
    [25]Merton C,Flemings.Behavior of metal alloys in the semisolid state.Metallic Transactions,1991,22B(6):269
    [26]Kenneth P,Young K O.Aluminium,1996,72(5):341
    [27]Young R M K,Clyne T W.A power-based approach to semisolid processing of metals for fabrication of die-casting and composites.Journal of Materials Science,1986,21:1057-1069
    [28]Antona R L,Moschini R.New foundry process for the production of light metals in the semi-liquid dough state.Metallic Science Technology,1986,4(2):49-59
    [29]张大辉,李延军,钟雪友.半固态铸造充型过程数值模拟研究新进展.热加工工 艺,2000,29(4):43-45
    [30]张大辉.半固态铝硅合金触变压缩变形机制及其流变规律的研究:[博士学位论文].北京:北京科技大学,2002
    [31]许珞萍,邵光杰,任忠鸣,等.电磁搅拌作用下非树枝晶铝合金组织演变过程的数学描述.中国有色金属学报,2002,12(1):52-56
    [32]李润娟.过共晶高铬铸铁半固态浆料制备及挤压成形:[硕士学位论文].昆明:昆明理工大学,2006
    [33]Toshio Haga,Kapranos E Simple rheocasting processes.Journal of Materials Processing Technology,2002,(130-131):594-598
    [34]Nomura H,Qiu P Q,Takita M.Semi-solid processing of cast iron.Materials Transactions,2001,42(2):303-306
    [35]毛卫民,赵爱民,钟雪友.半固态触变成形应用的新进展与前景展望.特种铸造及有色合金,1998,(6):33
    [36]陈体军,郝远.合金的半固态成形技术与应用.铸造,2001,50(11):645-649
    [37]Czerwinski F,Zielinska-lipiec A,Pinet P J.Correlating the microstructure and tensile properties of a thixomolded AZ91D magnesium alloy.Acta Materialia,2001,49(7):1225-1235
    [38]崔建忠,路贵民,刘丹,等.半固态浆料制备技术的新进展.哈尔滨工业大学学报,2000,32(4):110-113
    [39]张奎,刘国均,张景新,等.铝合金半固态加工技术应用.中国有色金属学报2000,10(增刊1):135-140
    [40]李士琦,杨卯生.钢铁材料半固态浆料制备与成形的研究现状与展望.河南冶金,2003,11(5):3-7
    [41]毛卫民,赵爱民,钟雪友,等.非枝晶半固态ZL101合金的电磁搅拌及触变成形研究.铸造,1999,(2):5-8
    [42]STEPHEN M P,BRISSING K.Semi-solid Casting of A1 Alloys:A Status Report.Modern Casting,1997,87(2):41-43
    [43]Joly P.A,Mehrabian R.The Rhelogy of a Partially Solid Alloy.Materials Science,1976(11):1393-1418
    [44]王平,路贵民,崔建忠.液相线半连续铸造A356铝合金二次加热合金组织与工 艺.材料导报,2002,16(5):72-74
    [45]杨必成,徐骏,田战锋,等.半固态铝合金AlSi6Mg2的二次加热工艺研究.热加工工艺,2005,34(6):37-39
    [46]王顺成,温景林,陈彦博,等.A2017半固态合金二次加热组织演变.东北大学学报(自然科学版),2003,24(11):1049-1052
    [47]宋建丽,游晓红,李天佑,等.半固态ZnAl27合金及其二次加热组织.金属热处理,2002,27(10):15-17
    [48]Garat M,Blais,Pluchon C,et al.Aluminum semi-solid processing:From the billet to the finished part.In:Bhasin A K,Moore J J,Young K P and Midson S.Proc of the 5th Int.Conf.on Semi-Solid Processing of Alloys and Composites,Golden,Colorado,June 23-25,1998,Colorado School of Mines:199-213
    [49]张奎,张永忠,刘国均,等.半固态AlSi7Mg合金二次加热工艺与组织转变机制.金属学报,1999,35(2):127-130
    [50]Mao Weimin,Cui Chenglin,Zhao Aimin,et al.The dynamically coarsing processes of the microstructures in the nondendritic AlSi7Mg alloy remelted in the semi-solid state.Transactions of Nonferrous Metals Society of China,2000,10(1):25-28
    [51]甄子胜,赵爱民,毛卫民,等.喷射沉积Al-30Si组织及其半固态保温转变规律.材料科学与工艺,2001,9(2):162-165
    [52]毛卫民,赵爱民,崔成林,等.半固态金属铸造的应用及研究现状.第二届有色合金及特种铸造国际会议,2001年5月4-6日,上海,中国:15-23
    [53]吴炳饶,戴挺.半固态触变成形坯料二次加热技术分析.特种铸造及有色合金,2000,20(6):58-61
    [54]郝石坚.高铬耐磨铸铁.北京:煤炭工业出版社,1993
    [55]李启衡.粉碎理论概要.北京:冶金工业出版社,1993
    [56]苏俊义.铬系耐磨白口铸铁.北京:国防工业出版社,1990
    [57]陈璟琚,许光奎,卿上胜,等.合金高铬铸铁及其应用.北京:冶金工业出版社,1999
    [58]皇志富,黄卫东,张安峰,等.半固态过共晶高铬铸铁的冲击及磨损性能研究.西安交通大学学报,2005,39(7):775-778
    [59]刑书明,张励忠,张国华,等.白口铸铁磨球半固态挤压铸造工艺参数设计.铸造,2002,51(7):431-434
    [60]田琴,周荣锋,蒋业华,等.倾斜板角度对亚共晶高铬铸铁半固态组织的影响.特种铸造及有色合金,2006,26(3):159-161
    [61]唐祁峰.过共晶高铬铸铁半固态流变挤压成形组织与性能研究:[硕士学位论文].昆明:昆明理工大学,2007
    [62]田琴.亚共晶高铬铸铁半固态浆料制备及挤压成形:[硕士学位论文].昆明:昆明理工大学,2006
    [63]中国机械工程学会铸造专业学会编.铸造手册(1)—铸铁.北京:机械工业出版社,2002
    [64]皇志富,刑建东,高义民.半固态过共晶高铬铸铁的制备及组织定量分析.铸造技术,2004,25(10):531-533
    [65]崔忠圻.金属学与热处理.北京:机械工业出版社,2000
    [66]杨昭.高铬铸铁半固态铸造:[博士学位论文].沈阳:中国科学院金属研究所,2003
    [67]王建宏,龙思远.挤压铸造模具材料的选用及热处理.铸造技术,2004,25(10):803-805
    [68]齐丕骧.挤压铸造.北京:国防工业出版社,1984

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700