本文主要研究内容
作者皮自强（2019）在《喷射成形过程控制及过喷粉末高效利用研究》一文中研究指出：高速钢被广泛用于制造各种切削工具和耐热耐磨零件。采用喷射成形工艺制备高速钢兼具快速冷却和近终成形的优点。但喷射成形工艺存在因参数多中间过程控制难以及易产生过喷粉末,造成原料利用率降低等问题,为此本研究基于河冶科技股份有限公司自主研发的4t级别喷射成形设备和实际生产过程,建立了喷射成形过程的综合数值模型;建立了高速钢过喷粉末的粉末冶金制备工艺,并以过喷粉末为原料制备了高性能W6Mo5Cr4V2Co5Nb(825K)高速钢,为提升喷射成形工艺在高速钢领域的应用奠定了理论和技术基础。主要结论如下:建立了金属液滴的动力学模型、热力学模型,尺寸分布模型,沉积坯的形状和温度场演变动态模型,用Matlab,Ansys和Thermo-calc软件对沉积坯糊状区固相率,沉积坯的形状和温度场演变过程进行了计算,并建立了糊状区固相率预测公式为:F=A1Vgi0.22 R0.19 Z0400-A2ΔT,其中A1、A2为比例系数,vgi为雾化气体初速度,RR为气液比,Z为沉积距离,ΔTT为过热度。当RR=0.55,vgi=300m/s,Z=0.5m,ΔT-100K时,W18Cr4V沉积坯糊状区固相率为71.48%,喷射过程中雾化锥中无未破碎金属液流,沉积坯表面无缺陷,组织均匀,模拟结果和实际符合。沉积坯形状控制的关键在于扫描轨迹和基底下拉速率的控制。扫描轨迹决定于喷嘴扫描频率和基底转速,扫描轨迹需满足均匀覆盖沉积坯表面,轨迹周期控制在10-15s较好。喷嘴偏心距,倾斜角以及喷射距离决定扫描轨迹的位置,喷嘴摆动角度,雾化系数以及喷射距离决定扫描轨迹的范围。基底下拉速率需满足v<K.SE.Acosφ(t),否则会造成严重过喷甚至喷射失败。建立的数学模型可被用于目标高速钢喷射参数的优化与推荐以及特定喷射参数下沉积坯状态的预测。计算优化后825K高速钢的推荐喷射参数为:主喷嘴初始偏心距0.12m,初始倾斜角17°,雾化系数0.0012m/s和60m-2,摆动频率3Hz,辅喷嘴初始偏心距0.20m,初始倾斜角40°,雾化系数0.003m/s,和1 50m-2,摆动频率3Hz,基底转速75rpm,下拉速率6.8× 10-4m/s,由此制备出了φ550mm重达3.4t的大截面喷射成形825K沉积坯,合金收得率92.1%,沉积坯致密度≥98%,氧含量39ppm,表面平整,底部过渡区比例小,经1 180℃淬火,540℃三次回火,硬度可达66.5HRC,抗弯强度3321MPa,优于铸造M35高速钢,推进了喷射成形高速钢的产业化进程。825K过喷粉末大部分呈球形,球形度随颗粒粒径减小而提高,内部为树枝晶,碳化物有M2C型和MC型。过喷粉末氧含量为240ppm,稳定非金属夹杂的含量为100.93ppm,其中Si02占91.03wt%,A1203为4.66wt%,其余为Ca、Mg、K、Ti等元素的氧化物,经800℃C氢气还原,磁选,过喷粉末的氧含量≤100ppm,非金属夹杂含量≤20ppm,为其利用奠定了基础。以过喷粉末为原料,采用两步法烧结(1200℃C/120min→1260℃C/30min),可制得致密度大于98%的825K合金,显微组织为渗碳体,铁素体,M6C型碳化物和MC型碳化物,其中M6C型碳化物富含W、Mo元素,晶粒内尺寸小于5μm,呈小块状,而在晶界处其最大尺寸可达12μm,呈不规则块状或条状,MC型碳化物富含V元素,尺寸小于3μm,呈弥散分布。烧结样品硬度可达51.8HRC,抗弯强度2042MPa,与水雾化粉末烧结高速钢性能相当。经过1180℃淬火,540℃回火后,样品显微组织为回火马氏体、M6C型碳化物、MC型碳化物和少量残余奥氏体,硬度可达64.2HRC,抗弯强度2857.70MPa,优于铸造CW6Mo5Cr4V3 合金(64～65.3HRC,2550MPa),实现了对过喷粉末的高效利用。
Abstract
gao su gang bei an fan yong yu zhi zao ge chong qie xiao gong ju he nai re nai mo ling jian 。cai yong pen she cheng xing gong yi zhi bei gao su gang jian ju kuai su leng que he jin zhong cheng xing de you dian 。dan pen she cheng xing gong yi cun zai yin can shu duo zhong jian guo cheng kong zhi nan yi ji yi chan sheng guo pen fen mo ,zao cheng yuan liao li yong lv jiang di deng wen ti ,wei ci ben yan jiu ji yu he ye ke ji gu fen you xian gong si zi zhu yan fa de 4tji bie pen she cheng xing she bei he shi ji sheng chan guo cheng ,jian li le pen she cheng xing guo cheng de zeng ge shu zhi mo xing ;jian li le gao su gang guo pen fen mo de fen mo ye jin zhi bei gong yi ,bing yi guo pen fen mo wei yuan liao zhi bei le gao xing neng W6Mo5Cr4V2Co5Nb(825K)gao su gang ,wei di sheng pen she cheng xing gong yi zai gao su gang ling yu de ying yong dian ding le li lun he ji shu ji chu 。zhu yao jie lun ru xia :jian li le jin shu ye di de dong li xue mo xing 、re li xue mo xing ,che cun fen bu mo xing ,chen ji pi de xing zhuang he wen du chang yan bian dong tai mo xing ,yong Matlab,Ansyshe Thermo-calcruan jian dui chen ji pi hu zhuang ou gu xiang lv ,chen ji pi de xing zhuang he wen du chang yan bian guo cheng jin hang le ji suan ,bing jian li le hu zhuang ou gu xiang lv yu ce gong shi wei :F=A1Vgi0.22 R0.19 Z0400-A2ΔT,ji zhong A1、A2wei bi li ji shu ,vgiwei wu hua qi ti chu su du ,RRwei qi ye bi ,Zwei chen ji ju li ,ΔTTwei guo re du 。dang RR=0.55,vgi=300m/s,Z=0.5m,ΔT-100Kshi ,W18Cr4Vchen ji pi hu zhuang ou gu xiang lv wei 71.48%,pen she guo cheng zhong wu hua zhui zhong mo wei po sui jin shu ye liu ,chen ji pi biao mian mo que xian ,zu zhi jun yun ,mo ni jie guo he shi ji fu ge 。chen ji pi xing zhuang kong zhi de guan jian zai yu sao miao gui ji he ji de xia la su lv de kong zhi 。sao miao gui ji jue ding yu pen zui sao miao pin lv he ji de zhuai su ,sao miao gui ji xu man zu jun yun fu gai chen ji pi biao mian ,gui ji zhou ji kong zhi zai 10-15sjiao hao 。pen zui pian xin ju ,qing xie jiao yi ji pen she ju li jue ding sao miao gui ji de wei zhi ,pen zui bai dong jiao du ,wu hua ji shu yi ji pen she ju li jue ding sao miao gui ji de fan wei 。ji de xia la su lv xu man zu v<K.SE.Acosφ(t),fou ze hui zao cheng yan chong guo pen shen zhi pen she shi bai 。jian li de shu xue mo xing ke bei yong yu mu biao gao su gang pen she can shu de you hua yu tui jian yi ji te ding pen she can shu xia chen ji pi zhuang tai de yu ce 。ji suan you hua hou 825Kgao su gang de tui jian pen she can shu wei :zhu pen zui chu shi pian xin ju 0.12m,chu shi qing xie jiao 17°,wu hua ji shu 0.0012m/she 60m-2,bai dong pin lv 3Hz,fu pen zui chu shi pian xin ju 0.20m,chu shi qing xie jiao 40°,wu hua ji shu 0.003m/s,he 1 50m-2,bai dong pin lv 3Hz,ji de zhuai su 75rpm,xia la su lv 6.8× 10-4m/s,you ci zhi bei chu le φ550mmchong da 3.4tde da jie mian pen she cheng xing 825Kchen ji pi ,ge jin shou de lv 92.1%,chen ji pi zhi mi du ≥98%,yang han liang 39ppm,biao mian ping zheng ,de bu guo du ou bi li xiao ,jing 1 180℃cui huo ,540℃san ci hui huo ,ying du ke da 66.5HRC,kang wan jiang du 3321MPa,you yu zhu zao M35gao su gang ,tui jin le pen she cheng xing gao su gang de chan ye hua jin cheng 。825Kguo pen fen mo da bu fen cheng qiu xing ,qiu xing du sui ke li li jing jian xiao er di gao ,nei bu wei shu zhi jing ,tan hua wu you M2Cxing he MCxing 。guo pen fen mo yang han liang wei 240ppm,wen ding fei jin shu ga za de han liang wei 100.93ppm,ji zhong Si02zhan 91.03wt%,A1203wei 4.66wt%,ji yu wei Ca、Mg、K、Tideng yuan su de yang hua wu ,jing 800℃Cqing qi hai yuan ,ci shua ,guo pen fen mo de yang han liang ≤100ppm,fei jin shu ga za han liang ≤20ppm,wei ji li yong dian ding le ji chu 。yi guo pen fen mo wei yuan liao ,cai yong liang bu fa shao jie (1200℃C/120min→1260℃C/30min),ke zhi de zhi mi du da yu 98%de 825Kge jin ,xian wei zu zhi wei shen tan ti ,tie su ti ,M6Cxing tan hua wu he MCxing tan hua wu ,ji zhong M6Cxing tan hua wu fu han W、Moyuan su ,jing li nei che cun xiao yu 5μm,cheng xiao kuai zhuang ,er zai jing jie chu ji zui da che cun ke da 12μm,cheng bu gui ze kuai zhuang huo tiao zhuang ,MCxing tan hua wu fu han Vyuan su ,che cun xiao yu 3μm,cheng mi san fen bu 。shao jie yang pin ying du ke da 51.8HRC,kang wan jiang du 2042MPa,yu shui wu hua fen mo shao jie gao su gang xing neng xiang dang 。jing guo 1180℃cui huo ,540℃hui huo hou ,yang pin xian wei zu zhi wei hui huo ma shi ti 、M6Cxing tan hua wu 、MCxing tan hua wu he shao liang can yu ao shi ti ,ying du ke da 64.2HRC,kang wan jiang du 2857.70MPa,you yu zhu zao CW6Mo5Cr4V3 ge jin (64～65.3HRC,2550MPa),shi xian le dui guo pen fen mo de gao xiao li yong 。
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论文作者分别是来自北京科技大学的皮自强，发表于刊物北京科技大学2019-06-27论文，是一篇关于喷射成形论文,数值模拟论文,高速钢论文,粉末冶金论文,性能论文,北京科技大学2019-06-27论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自北京科技大学2019-06-27论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。