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Austenite Grain Growth Calculation during Hot Rolling of 0.028% Nb Steel 被引量:1
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作者 Dedi Priadi Richard Alfonso Mangaraja Napitupulu Eddy Sumamo Siradj 《材料科学与工程(中英文A版)》 2011年第5X期678-683,共6页
关键词 奥氏体晶粒长大 热轧过程 铌钢 奥氏体晶粒尺寸 计算 nb 轧制温度 热连轧机
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Nb对铁素体不锈钢耐铝液腐蚀性能的影响
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作者 宋佳敏 袁美怡 杨弋涛 《铸造》 CAS 2024年第7期968-974,共7页
研究了Nb含量对铁素体不锈钢的耐铝液腐蚀性能的影响及相关机理。不同含量的Nb元素对试样基体中的第二相分布有影响,这些第二相具有阻碍铝液腐蚀的作用。铁素体不锈钢在铝液中浸蚀后,会在界面处生成金属间化合物层,基体中Nb元素的含量... 研究了Nb含量对铁素体不锈钢的耐铝液腐蚀性能的影响及相关机理。不同含量的Nb元素对试样基体中的第二相分布有影响,这些第二相具有阻碍铝液腐蚀的作用。铁素体不锈钢在铝液中浸蚀后,会在界面处生成金属间化合物层,基体中Nb元素的含量会影响碳化物生成和聚集位置,从而导致耐铝液腐蚀性能的差异。试验结果表明:添加0.2wt.%的Nb元素,可以获得细小弥散第二相,最终获得优异的耐铝液腐蚀性能。 展开更多
关键词 铁素体不锈钢 nb 显微组织 铝液 腐蚀
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Mg处理Nb-Ti微合金钢中非金属夹杂物演变机理研究
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作者 朱吴杰 王德永 +2 位作者 孙群 温荣宇 屈天鹏 《炼钢》 CAS 北大核心 2024年第4期40-51,共12页
在工业生产条件下,对Nb-Ti微合金钢进行Mg处理试验,分析了Mg处理条件下,微合金钢中非金属夹杂物的演变规律。结果表明,微合金钢经过铝脱氧产物主要为Al_(2)O_(3)夹杂,进行Ca处理后,Al_(2)O_(3)夹杂减少,转变为CaO-Al_(2)O_(3)夹杂,且部... 在工业生产条件下,对Nb-Ti微合金钢进行Mg处理试验,分析了Mg处理条件下,微合金钢中非金属夹杂物的演变规律。结果表明,微合金钢经过铝脱氧产物主要为Al_(2)O_(3)夹杂,进行Ca处理后,Al_(2)O_(3)夹杂减少,转变为CaO-Al_(2)O_(3)夹杂,且部分MnS夹杂转变为CaS夹杂;精炼阶段将Ca处理改为Mg处理后,可将铝脱氧产物Al_(2)O_(3)夹杂变性为MgO-Al_(2)O_(3)夹杂。Mg处理前,夹杂物在LF主要是Al_(2)O_(3)夹杂,进行Mg处理和Ti合金化后,钢中主要夹杂物变为MgO-Al_(2)O_(3)夹杂、MgO夹杂和TiN夹杂,最终在铸坯中的夹杂物为MgO-Al_(2)O_(3)外包裹CaS/MnS和(Nb、Ti)N复合夹杂。对Ca处理和Mg处理的夹杂物尺寸进行对比,夹杂物尺寸主要分布在5μm以内,Mg处理形成的2μm以内的夹杂物占比高于Ca处理工艺,表明镁处理可以较好地细化夹杂物,形成大量弥散分布的细小夹杂,有助于提升钢的综合力学性能。 展开更多
关键词 Mg处理 nb-TI微合金钢 非金属夹杂物 热力学分析
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中碳CrMo钢中Ti、Nb液析形貌及生成机理分析 被引量:1
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作者 蒋乔 张健 倪燕红 《特殊钢》 2024年第2期18-23,共6页
通过观察微合金Ti、Nb、V在42CrMo钢连铸坯中的液析形貌,以及液析经加热轧制后的变化,同时,采用热力学计算的方式推导液析生成机理。结果表明,在含w[Ti]0.012%、w[Nb]0.030%、w[V]0.030%、w[N]0.003 5%的42CrMo钢410 mm×530 mm连... 通过观察微合金Ti、Nb、V在42CrMo钢连铸坯中的液析形貌,以及液析经加热轧制后的变化,同时,采用热力学计算的方式推导液析生成机理。结果表明,在含w[Ti]0.012%、w[Nb]0.030%、w[V]0.030%、w[N]0.003 5%的42CrMo钢410 mm×530 mm连铸坯中,可观察到Ti、Nb以复合碳氮化物的形式析出,形成微米级液析,w[Ti]较高(70%~83%)的多呈多边形块状,w[Nb]较高(70%~85%)的多呈薄膜状或不规则块状,液析中基本不含V元素;Ti和Nb的碳氮化物液析可互溶并共同生长,Nb含量较高的液析以Ti含量较高的液析为核心长大为块状,部分液析以含硫夹杂物为核心形核并长大;连铸坯心部的碳氮化物液析较多,并且尺寸较大(最长达35μm),连铸坯表面的数量较少,尺寸较小(10μm以下);连铸坯经1 200℃加热并轧制后,液析可部分回溶,数量减少,尺寸减小,并且在轧制过程中破碎。 展开更多
关键词 TI nb CrMo 微合金 中碳钢 液析
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Nb含量对X70钢级直缝埋弧焊管组织及强韧性的影响
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作者 何小东 张永青 +2 位作者 HAN David 陈越峰 杨耀彬 《钢管》 CAS 2024年第1期29-34,共6页
检测了Nb含量为0.046%和0.075%的X70直缝埋弧焊管的强韧性,分析了管体的微观组织。结果表明:随着Nb含量升高,管体的平均晶粒尺寸减小,组织由PF+B_(粒)转变为以B_(粒)为主;管体横向拉伸应力-应变曲线均为典型的“拱顶”型,拉伸性能均满... 检测了Nb含量为0.046%和0.075%的X70直缝埋弧焊管的强韧性,分析了管体的微观组织。结果表明:随着Nb含量升高,管体的平均晶粒尺寸减小,组织由PF+B_(粒)转变为以B_(粒)为主;管体横向拉伸应力-应变曲线均为典型的“拱顶”型,拉伸性能均满足要求,但含量为0.075%Nb的管体的横向屈服强度和抗拉强度较高;Nb含量相同时,C含量越高,其屈服强度和抗拉强度越高;含量为0.075%Nb的钢管具有更好的低温冲击韧性,但含量为0.046%Nb的钢管的韧-脆转变曲线具有更高的上平台能。Nb含量较高、C含量较低的钢管的热影响区也具有更好的低温韧性。探讨了C、Nb元素的含量及组织类型、析出相和位错密度对X70管线钢强韧性的影响。 展开更多
关键词 直缝埋弧焊管 管线钢 X70 铌含量 微观组织 强韧性
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热处理工艺及Nb微合金化对9Ni钢组织性能的影响
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作者 刘朝霞 孙宪进 +3 位作者 刘俊 叶建军 王柯 徐光琴 《特殊钢》 2024年第3期70-74,共5页
为了适应LNG燃料罐、储罐使用需要,对9Ni钢进行冶炼、轧制关键工艺控制,研究两相区热处理工艺及Nb微合金化对组织性能的影响。结果表明,随着亚温淬火温度的升高,屈服强度、抗拉强度、屈强比先降低后升高。随着回火温度的升高,屈服强度... 为了适应LNG燃料罐、储罐使用需要,对9Ni钢进行冶炼、轧制关键工艺控制,研究两相区热处理工艺及Nb微合金化对组织性能的影响。结果表明,随着亚温淬火温度的升高,屈服强度、抗拉强度、屈强比先降低后升高。随着回火温度的升高,屈服强度与抗拉强度逐渐降低,伸长率升高;当回火温度为600℃时,屈服强度与抗拉强度达到最低值,伸长率达到最高值。亚温淬火态组织呈现大、小晶粒并存状态,有助于降低钢板屈强比。Nb微合金化9Ni钢板成品组织主要为回火索氏体组织及3%~8%残余奥氏体。0.015%Nb的加入使9Ni钢平均屈服强度提高约50 MPa,抗拉强度提高约40 MPa,-196℃横向夏比V型冲击吸收能提高约40 J。 展开更多
关键词 LNG nb微合金化 9NI钢 回火索氏体
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N、Nb合金化对309S奥氏体不锈钢腐蚀性能的影响
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作者 王聪 王春妮 +4 位作者 刘后龙 刘星辰 李兰云 宰伟 余中狄 《表面技术》 EI CAS CSCD 北大核心 2024年第22期82-91,126,共11页
目的以高放废液封装容器材料309S奥氏体不锈钢为研究对象,通过N、Nb联合添加改善不锈钢在Cl~-环境中的耐蚀性能,并探究N、Nb元素对不锈钢耐蚀性能的影响机理。方法采用扫描电镜、X射线衍射、形状测量激光扫描系统、X射线光电子能谱等手... 目的以高放废液封装容器材料309S奥氏体不锈钢为研究对象,通过N、Nb联合添加改善不锈钢在Cl~-环境中的耐蚀性能,并探究N、Nb元素对不锈钢耐蚀性能的影响机理。方法采用扫描电镜、X射线衍射、形状测量激光扫描系统、X射线光电子能谱等手段,对不锈钢的微观组织及钝化膜成分进行分析,从击穿电位、极化电阻及腐蚀形貌等方面揭示了N、Nb元素对不锈钢耐腐蚀性能的影响机理。结果N的添加可以促进含Nb钢中耐蚀的Nb(C,N)析出以及难溶的Nb_(2)O_(5)腐蚀产物形成。同时,部分N转化为NH_(3)/NH_(4)^(+),提高局部pH,有利于表面再钝化。因此,N、Nb联合添加的309S不锈钢展现出优异的耐蚀性能。相比商用309S不锈钢,添加0.17%(质量分数)N和0.45%(质量分数)Nb的不锈钢在3.5%(质量分数)Na Cl溶液中击穿电位由0.20 V提升至0.96 V,自腐蚀电流密度从2.529×10^(-7)A/cm^(2)减小到0.793×10^(-7)A/cm^(2)。6%FeCl_(3)-0.16%HCl(质量分数)溶液浸泡腐蚀120 h后,N、Nb联合添加的不锈钢点蚀坑数目最少,平均表面粗糙度(S_(a))、最大点蚀坑宽度(W_(max))和最大点蚀坑深度(D_(max))均最小,展现出良好的耐蚀性能;仅添加Nb不添加N的不锈钢其击穿电位略低于309S不锈钢,S_(a)最大,点蚀坑向纵深方向扩展严重。结论N、Nb联合添加能有效抑制点蚀坑的萌生与扩展,显著提高不锈钢耐腐蚀性能,而单独添加Nb效果较差。 展开更多
关键词 309S不锈钢 N、nb联合添加 腐蚀性能 协同作用
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再结晶区变形后冷却速率对Nb-V-Ti-N微合金钢组织演变及力学性能的影响
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作者 张婧 赵志博 +3 位作者 辛文彬 谷静远 罗果萍 彭军 《材料热处理学报》 CAS CSCD 北大核心 2023年第9期94-105,共12页
利用Gleeble-3800热/力模拟机研究了Nb-V-Ti-N微合金钢的动态连续冷却转变规律,并探讨了再结晶区变形后冷速对其组织及性能的影响。结果表明:当冷速由0.1℃/s增大至30℃/s时,实验钢发生铁素体、珠光体、贝氏体和马氏体相变,冷速区间分别... 利用Gleeble-3800热/力模拟机研究了Nb-V-Ti-N微合金钢的动态连续冷却转变规律,并探讨了再结晶区变形后冷速对其组织及性能的影响。结果表明:当冷速由0.1℃/s增大至30℃/s时,实验钢发生铁素体、珠光体、贝氏体和马氏体相变,冷速区间分别为0.1~30℃/s、0.1~8℃/s、3~30℃/s和15~30℃/s;随着冷速的增大,铁素体、珠光体和贝氏体相变温度分别由785、682和498℃降低到625、553和415℃,而马氏体相变温度则由342℃升高为365℃。当冷速由3℃/s增大至8、20和30℃/s时,钢中大角度晶界占比由0.734不断减少到0.509;平均有效晶粒尺寸先由10.62μm减小到7.46μm后增大到9.61μm,最小值在20℃/s获得;平均KAM值先由0.419°略降低到0.407°后升高到0.691°,最小值在8℃/s获得。此外,当冷速由0.1℃/s增大至30℃/s,实验钢的显微硬度由(197±23.3)HV0.1逐渐增加到(316±11.8)HV0.1,屈服强度由(475±67.1)MPa增加到(818±33.9)MPa。分析可知,为了获得良好的强度-韧性配合,实验钢再结晶区变形后适宜的冷速为8℃/s。 展开更多
关键词 nb-V-Ti-N微合金钢 冷却速率 组织演变 动态连续冷却转变曲线 力学性能
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Nb对H13钢高温摩擦磨损性能的影响
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作者 周健 欧阳伟豪 +2 位作者 方峰 廖俊 马志俊 《材料热处理学报》 CAS CSCD 北大核心 2023年第10期155-164,共10页
在不同温度下,采用高温摩擦磨损试验机对不同Nb含量的H13热作模具钢进行了摩擦磨损试验,利用扫描电镜(SEM)、显微硬度计、白光干涉仪、背散射电子衍射和能谱仪等研究了试验钢的磨损表面及截面形貌和硬度,并分析了Nb含量对试验钢高温磨... 在不同温度下,采用高温摩擦磨损试验机对不同Nb含量的H13热作模具钢进行了摩擦磨损试验,利用扫描电镜(SEM)、显微硬度计、白光干涉仪、背散射电子衍射和能谱仪等研究了试验钢的磨损表面及截面形貌和硬度,并分析了Nb含量对试验钢高温磨损性能及磨损机制的影响。结果表明:相同试验温度下,随Nb含量增加,试验钢的摩擦系数降低,在500℃时达到最低值;随Nb含量的增加,试验钢磨损率逐渐降低,耐磨性逐渐提高。Nb的加入对试验钢表面软化层的硬度下降有一定抑制作用,对氧化层的支撑作用增强,氧化层剥落机率降低,耐磨性提高。不同Nb含量的H13钢的磨损机理主要是氧化磨损。 展开更多
关键词 nb热作模具钢 高温摩擦磨损 摩擦系数 高温氧化 表面软化
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Mathematical Modelling of Carbonitride Precipitation during Hot Working in Nb Microalloyed Steels 被引量:2
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作者 Yunbo XU Yongmei YU Xianghua LIU Guodong WANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第2期149-152,共4页
Based on thermodynamics and kinetics, precipitation behavior of microalloyed steels was analyzed. Deformation greatly promotes isothermal carbonitride precipitation and makes C-curve shift leftwards. The position and ... Based on thermodynamics and kinetics, precipitation behavior of microalloyed steels was analyzed. Deformation greatly promotes isothermal carbonitride precipitation and makes C-curve shift leftwards. The position and shape of C-curve also depend on the content of Nb and N. C-curve shifts leftwards a little when N content increases and the nose temperature is raised with increasing Nb content. Deformation shortened precipitation start time during continuous cooling, raised precipitation start temperature, accelerated precipitation kinetics of carbonitrides. With decreasing the finishing temperature and coiling temperature, the precipitates volume fraction increases and strength increment is raised during hot rolling. The simulated results are in agreement with experiment results. 展开更多
关键词 nb microalloyed steels Precipitation kinetics Precipitation-temperature-time curve Continuous cooling precipitation Mathematical modeling
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Balanced solubility product and enthalpies of formation of Nb compounds in 0.09 % oriented silicon steel 被引量:6
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作者 Hui Li Yun-Li Feng +2 位作者 Dan Zhang Meng Song Da-Qiang Cang 《Rare Metals》 SCIE EI CAS CSCD 2013年第3期318-322,共5页
Balance solubility products and enthalpy of for- mation for NbC0.75, NbC0.85, NbC0.88, NbC and NbN in oriented silicon steels were calculated and compared quali- tatively. Meanwhile, the mixing enthalpies of these fiv... Balance solubility products and enthalpy of for- mation for NbC0.75, NbC0.85, NbC0.88, NbC and NbN in oriented silicon steels were calculated and compared quali- tatively. Meanwhile, the mixing enthalpies of these five Nb compounds were calculated based on Miedema Model. The results show that the solubility products of Nb compounds in ferrite and austenite meet the following relationship, NbC0.75 〉 NbC0.85 〉 NbC0.88 〉 NbC 〉 NbN and NbN has the minimum enthalpy of formation. It indicates that NbN easily precipitate out, but it is more difficult for NbC0.75. 展开更多
关键词 Oriented silicon steel nb compounds Solubility formula Enthalpy of formation
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Precipitation Behavior of Nb in Steel under Ultra Fast Cooling Conditions 被引量:2
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作者 周晓光 WANG Meng +3 位作者 LIU Zhenyu YANG Hao WU Di WANG Guodong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期375-379,共5页
By measuring the expansion curves of a Nb bearing steel at different cooling rates by using Gleeble-3800 thermomechanical simulator, combining with metallographic analysis, different phase zones were determined. Also,... By measuring the expansion curves of a Nb bearing steel at different cooling rates by using Gleeble-3800 thermomechanical simulator, combining with metallographic analysis, different phase zones were determined. Also, precipitation behavior of Nb at different phase zones was investigated under ultra fast cooling conditions. The experimental results showed that adopting a proper deformation temperature, the ultra fast cooling process can restrain the precipitation of Nb at austenite phase zone. More quantities and smaller size precipitates of Nb can be found at the ferrite or bainite phase zone by controlling the ultra fast cooling ending temperature. With the increase of holding time at austenite, ferrite and bainite phase zones respectively, the volume fraction of precipitation, density, and average size of precipitates will increase obviously. With the decrease of early ultra fast cooling ending temperature, the density of Nb precipitates first increase(at ferrite phase zone) and then decrease(at bainite phase zone), the volume fraction of Nb precipitation decreases and precipitates can be refined. The optimal early ultra fast cooling ending temperature is located at ferrite phase zone. The combination of high rolling temperature with early ultra fast cooling technology opens the way for new cooling schedules and makes the production of high strength steels easier and cheaper by making full use of Nb precipitation strengthening effect. 展开更多
关键词 nb bearing steel precipitation ultra fast cooling microstructure
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MODELING OF STATIC RECRYSTALLIZATION KINETICS OF Nb-BEARING STEELS 被引量:3
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作者 L.Q. Ma Z.Y. Liu +2 位作者 S.H. Jiao X.Q. Yuan D. Wu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2006年第4期271-278,共8页
By using isothermal double hit compression tests and applying the 2% offset method, a new model was developed to predict the microstructural evolution of Nb-bearing steels at temperatures above and below the start tem... By using isothermal double hit compression tests and applying the 2% offset method, a new model was developed to predict the microstructural evolution of Nb-bearing steels at temperatures above and below the start temperature of strain-induced precipitation (Tp). The Tp was developed as a function of true strain, initial austenite grain size and the Nb content. The activation energy of static recrystallization (Qrex) was expressed as a function of the content of different alloy elements. It was found that Nb played the most important role in increasing the value of Qrex, The microstructural observations and measurements confirmed the validity of the model developed in the present investigation. 展开更多
关键词 nb-bearing steel static recrystallization Tp (start temperature of strain-induced precipitation) activation energy
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Role of Rare Earth in Low Sulphur Nb-Ti-Bearing Steel 被引量:5
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作者 朱兴元 林勤 +3 位作者 曾静 刘继雄 高平祥 王跃华 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第1期81-85,共5页
The effect of rare earth on the microstructures, mechanical properties and inclu sions in low sulphur Nb-Ti-bearing steel were investigated. It is shown that t h e transverse yield point, the traverse tensile strength... The effect of rare earth on the microstructures, mechanical properties and inclu sions in low sulphur Nb-Ti-bearing steel were investigated. It is shown that t h e transverse yield point, the traverse tensile strength and elongation of testin g steels decrease initially and then rise with increasing content of rare earth. The impact energy values of the testing steels exhibit a contrary trend. Proper amount of rare earth in the steels can improve the anisotropy of impact toughne ss above -20 ℃ and it does not affect the type of microstructures which ar e st ill composed of ferrites and pearlites, but the pearlite amount increases. On one hand, rare earth cleans the molten steel and reduces the amount of inclusions; on the other hand, rare earth makes the inclusions spheroidizd, refi ned and dispersed, and thus improves the distribution of inclusions. 展开更多
关键词 metal materials nb-Ti-bearing steel prop erty microstructure INCLUSION rare earths
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Effect of Nb on the transformation kinetics of low carbon(manganese) steel during deformation of undercooled austenite 被引量:3
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作者 Guoan Chen Wangyue Yang +1 位作者 Shouzhen Guo Zuqing Sun 《Journal of University of Science and Technology Beijing》 CSCD 2006年第5期411-415,共5页
The hot compression tests using Gleeble 1500 were performed by varying the true strain up to 1.6 (80% reduction) in Nbfree and Nb-microalloyed steels. The effect of Nb addition on the transformation kinetics during ... The hot compression tests using Gleeble 1500 were performed by varying the true strain up to 1.6 (80% reduction) in Nbfree and Nb-microalloyed steels. The effect of Nb addition on the transformation kinetics during deformation of undercooled austenite was investigated. It was found that as compared with Nb-free steel, the transformation incubation period of Nb-bearing steel was prolonged and the transformation kinetics curves parallelly moved to higher strain because of the solute Nb drag effect. Studies on kinetics also showed that the deformation-enhanced ferrite transformation (DEFT) of the two steels were composed of three stages, which can be expressed by the J-M-A equations individually. However, the parameter n related to the mode of nucleation and growth is somewhat different in the first and second stages of the two steels, and the same in the third stage for both the steels corresponding to the nucleation Of retained austenite. 展开更多
关键词 nb-microalloyed steel deformation-enhanced ferrite transformation transformation kinetics J-M-A equations
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The effect of V-Nb on the growth of austenite grains in 17CrNiMo6 gear steel 被引量:5
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作者 Zhao Yaping Wang Maoqiu Yuan Jiguo 《Baosteel Technical Research》 CAS 2008年第2期46-50,共5页
This study researches the effect of V-Nb on the growth of austenite grains in 17CrNiMo6 carburized gear steel. Results show that the carbonitride in V and Nb acts as second-phase particles in the steel, which can be u... This study researches the effect of V-Nb on the growth of austenite grains in 17CrNiMo6 carburized gear steel. Results show that the carbonitride in V and Nb acts as second-phase particles in the steel, which can be used to block the migration of grain boundaries and the thinning of the austenite grains. This causes the crystals in the V-Nb microalloy 17CrNiMo6 steel to coarsen and the temperature to rise, thus reducing the cost of the carbonization that follows processing on the gears. 展开更多
关键词 V-nb microalloy 17CrNiMo6 steel austenite grain pinning effect
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Characteristics of microstructural evolution during deformation-enhanced ferrite transformation in Nb-microalloyed HSLA steel 被引量:2
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作者 Guoan Chen Wangyue Yang +1 位作者 Shouzhen Guo Zuqing Sun 《Journal of University of Science and Technology Beijing》 CSCD 2007年第1期36-40,共5页
Microstructure evolution during deformation of undercooled austenite at 760℃ was investigated in Nb-microalloyed steel by using SEM (scanning electron microscope), TEM (transmission electron microscope), and EBSD... Microstructure evolution during deformation of undercooled austenite at 760℃ was investigated in Nb-microalloyed steel by using SEM (scanning electron microscope), TEM (transmission electron microscope), and EBSD (electron backscattered diffraction). It is indicated that during deformation-enhanced ferrite transformation (DEFT) in Nb-microalloyed steel, the incubation period is prolonged, and the higher strain is needed to accomplish ferrite transformation. Therefore, the transformation kinetics curves move to high strain parallelly; and the transformation kinetics curves of Nb-microalloyed steel can be divided into three stages. At the fast stage, the solute drag effect of Nb and the consumption of strain energy for the dynamic precipitation of Nb(CN) led to a long incubation period, and at the second stage, ferrite transformation was accelerated significantly and fine Nb(CN) precipitates restrict the grain growth of ferrite effectively. The results also showed that DEFT in Nb-microalloyed steel is still a nucleation dominated process, and during the microstructure evolution the interchange of 〈001〉 and 〈111〉 texture was obtained. 展开更多
关键词 nb-microalloyed steel deformation-enhanced ferrite transformation (DEFT) microstructure evolution transformation kinetics TEXTURE
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Dynamic Recrystallization Behaviour of Nb-Ti Microalloyed Steels 被引量:3
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作者 MA Liqiang LIU Zhenyu +2 位作者 JIAO Sihai YUAN Xiangqian WU Di 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第4期551-557,共7页
The dynamic recrystallization (DRX) behavior of Nb-Ti microalloyed steels was investigated by isothermal single compression tests in the temperature range of 900-1 150 ℃ at constant strain rates of 0.1-5 s^-1. DRX ... The dynamic recrystallization (DRX) behavior of Nb-Ti microalloyed steels was investigated by isothermal single compression tests in the temperature range of 900-1 150 ℃ at constant strain rates of 0.1-5 s^-1. DRX was retarded effectively at low temperature due to the onset of dynamic precipitation of Nb and Ti carbonitrides, resulting in higher values of the peak strain. An expression was developed for the activation energy of deformation as a function of the contents of Nb and Ti in solution as well as other alloying elements. A new value of corrective factor was determined and applied to quantify the retardation produced by increase in the amount of Nb and Ti dissolved at the reheating temperature. The ratio of critical strain to peak strain decreases with increasing equivalent Nb content. In addition, the effects of Ti content and deformation conditions on DRX kinetics and steady state grain size were determined. Finally, the kinetics of dynamic precipitation was determined and effect of dynamic precipitation on the onset of DRX was clarified based on the comparison between precipitate pinning force and recrystallization driving force. 展开更多
关键词 nb-Ti microalloyed steels dynamic recrystallization activation energy of deformation dynamic precipitation
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Nb含量对低合金高强钢微观组织和力学性能的影响 被引量:1
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作者 林轩艺 王红鸿 鄢文泽 《武汉科技大学学报》 CAS 北大核心 2023年第3期175-179,共5页
本研究设计了4组Nb添加量依次为0、0.025%、0.085%、0.180%的低合金高强钢,通过OM、SEM/EDS和力学性能测试,研究了Nb微合金钢的微观组织和强韧化机制。结果表明,未添加Nb的钢组织由粗大的多边形铁素体和少量贝氏体组成,而Nb微合金钢组... 本研究设计了4组Nb添加量依次为0、0.025%、0.085%、0.180%的低合金高强钢,通过OM、SEM/EDS和力学性能测试,研究了Nb微合金钢的微观组织和强韧化机制。结果表明,未添加Nb的钢组织由粗大的多边形铁素体和少量贝氏体组成,而Nb微合金钢组织主要由细小的针状铁素体和贝氏体构成,且随着Nb含量的增加,析出相NbC的数量增多,晶粒逐渐细化。当Nb含量为0.085%时,钢具有最佳的综合力学性能,这可以归因于硬质相贝氏体以及细小的晶粒所带来的细晶强化作用,另一方面,弥散分布的细小析出相NbC(尺寸分布在50~300 nm)保证了钢的组织均匀性,0.085%Nb钢表现出最为稳定的低温冲击韧性。 展开更多
关键词 nb微合金化 低合金高强钢 nb含量 细晶强化 nbC 低温冲击韧性
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Bainite Transformation Under Continuous Cooling of Nb-Microalloyed Low Carbon Steel 被引量:10
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作者 YI Hai-long DU Lin-xiu WANG Guo-dong LIU Xiang-hua 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第3期36-39,67,共5页
Utilizing Gleeble-1500 thermomechanical simulator, the influences of hot deformation parameters on continuous cooling bainite transformation in Nb-microalloyed low carbon steel were investigated. The results indicate ... Utilizing Gleeble-1500 thermomechanical simulator, the influences of hot deformation parameters on continuous cooling bainite transformation in Nb-microalloyed low carbon steel were investigated. The results indicate that bainite starting temperature decreases with raising cooling rate and increases with increasing deformation temperature. Deformation has an accelerative effect on the bainite transformation when the specimens are deformed at 950 ℃. When the deformation temperature increases, the effect of deformation on bainite starting temperature is weakened. The amount of bainite is influenced by strain, cooling rate, and deformation temperature. When the specimens are deformed below 900 ℃, equiaxed ferrites are promoted and the bainite transformation is suppressed. 展开更多
关键词 nb-microalloyed low carbon steel bainite starting temperature BAINITE equiaxed ferrite retained austenite
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