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研究了含硅量为1.5%(质量分数)的高硅马氏体型热作模具钢(SDH3)的内耗谱与显微结构之间的关系.实验用SDH3钢采用1060℃保温30min油冷淬火和不同回火工艺处理.试样的温度-内耗谱(TDIF)的测量在振动仪上进行,采用自由衰减法,测量温度区间为室温至750℃.实验结果表明:SDH3钢的TDIF谱线主要是Snoek峰和SKK峰这两种机制的内耗峰;随着回火温度的升高,内耗峰峰高均逐渐降低,并且峰位也发生改变;当回火温度达到650℃时,内耗峰完全消失而只剩下背景内耗;随着回火保温时间的延长,内耗峰峰高和峰位都发生变化,并从扩散控制再分配机理的角度对这些变化进行了分析讨论. 相似文献
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张凤明梁正伟薛虎东王嘉伟 《包钢科技》2022,(4):51-54
在实验室进行了不同稀土Ce含量的热轧态U75V钢轨冶炼及轧制,重点针对轧后钢轨低温冲击性能、低温断裂韧性进行对比分析。试验结果表明,热轧态U75V钢轨加入0.0056%稀土Ce后,钢轨常温冲击韧性可提高30%左右,-60℃低温冲击韧性可提高60%左右;钢轨-20℃KIC平均值提高14%左右,钢轨-60℃KIC平均值提高15%左右,稀土Ce的加入进一步提升了热轧态U75V钢轨低温韧性。 相似文献
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针对低碳贝氏体钢,采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射和内耗手段分析了600℃回火过程中的显微组织变化,测试了回火后的屈服强度。结果表明,试验钢轧制态的显微组织是板条贝氏体与粒状贝氏体的混合组织,有少量Mo_2C和NbC析出。随着回火时间延长,贝氏体板条的宽度不断增大,板条内部形成较多不同取向的胞状结构,有些板条逐步演化为多边形状,粒状贝氏体不断吞噬板条贝氏体,使显微组织中粒状贝氏体增多且粗化;Mo_2C和NbC析出物进一步增多,贝氏体铁素体中的位错密度不断降低;内耗-温度谱中Snoek峰值不断降低,表面处的SKK峰值先降低后升高,心部的SKK峰值先降低后变化不大;屈服强度呈现先提高后降低的趋势。 相似文献
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测定了ULC-BH钢1 mm退火冷轧钢板(/%:0.002C,0.008Si,0.60Mn,0.043P,0.009S,0.031Al,0.071Ti)经2%~10%预应变,170℃20 min烘烤后的烘烤硬化(BH)值,通过内耗实验获得不同应变时效下的内耗谱线,利用X射线衍射技术测定位错密度,研究了Cottrell气团对ULC-BH钢烘烤硬化性能的影响。结果表明,随预应变量增加,ULC-BH钢的BH值增大;随预应变量增加,Snoek峰逐渐降低,而SKK峰逐渐升高;经2%、6%和10%预应变,位错密度增大,分别为3.9×1010/cm~2,8.4×1010/cm2和6.8×1011/cm2,相应的Cottrell气团密度逐渐减小。 相似文献
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采用含有不同含量磷的电子轰击纯铁作样品,经脱碳脱氮后,用低频倒扭摆测量其300—800℃之间的内耗值。结果表明,磷含量在0.007—0.28wt%之间的五根样品,分别于580℃和470℃左右出现两个内耗峰,激活能分别为2.13ev和1.80ev。经高温保温一定时期淬火处理后,这两个峰全部消失。由此看出,580℃左右的峰可能是Fe—p的ss峰,而470℃的峰可能是纯铁的PM峰。
本文还研究了一根含稀土元素铈的铁磷合金的内耗。发现在703℃、601℃和500℃相应出现三个内耗峰。初步认为,它们分别是Fe—Ce的ss峰、Fe—P的ss峰和纯铁的PM峰。 相似文献
本文还研究了一根含稀土元素铈的铁磷合金的内耗。发现在703℃、601℃和500℃相应出现三个内耗峰。初步认为,它们分别是Fe—Ce的ss峰、Fe—P的ss峰和纯铁的PM峰。 相似文献
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Internal Friction in Rail Waist of BNb and BNbRE Steels 总被引:1,自引:0,他引:1
The experi ments showed that the inclusions andpearlite of the steel were modified and/or refined ,andthe plasticity ,toughness , wearability as well as theservice life of the rail were obviouslyi mproved by add-ing RE.It was firstlyfoundthat as a result of additionof REinthe steel ,there appeared an obvious inhibit-ing and/or di minishing effect on the fatigue damage ,particularly on both nuclear damage and rail waistdamage[1 ,2]. However , whether the initiation and ex-tension of the residi… 相似文献
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Yu Ning Sun Zhenyan Ji Jingwen Ren Xinjia Wang Yunsheng Wang Longmei 《中国稀土学报(英文版)》2005,23(5):646-646
Effect of Rare Earth (Niobium) on Costed and Hot-Rolled Microstructure and Properties of Heavy Rail Steels 相似文献
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Effect of Rare Earths on Properties of BNbRE Rail Steel 总被引:1,自引:0,他引:1
The development and properties of BNbRE rail steel and the effect of RE on rail steel were studied. The results show that the properties of rail steel (δb ≥980 MPa, δ5≥ 8 % ) can be improved by adding RE and niobium and adjusting the content of C, Si and Mn in steel. At the same time, the abrasion resistance, contact fatigue and fatigue property of BNbRE rail steel are excellent. It also shows that RE in rail steel has the functions of purifying steel, modifying inclusion and micro-alloy action effect. The improved steel-making process enhances the quality of molten steel. Although the content of RE is low, excellent properties of BNbRE rail steel are achieved. 相似文献
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Il-Chan Jung Deok-Gu Kang Bruno C. De Cooman 《Metallurgical and Materials Transactions A》2014,45(4):1962-1978
The simultaneous presence of interstitial solutes and dislocations in an ultra-low carbon bake-hardenable steel gives rise to two characteristic peaks in the internal friction (IF) spectrum: the dislocation-enhanced Snoek peak and the Snoek–Kê–Köster peak. These IF peaks were used to study the dislocation structure developed by the pre-straining and the static strain aging effect of C during the bake-hardening process. A Ti-stabilized interstitial-free steel was used to ascertain the absence of a γ-peak in the IF spectrum of the deformed ultra-low carbon steel. The analysis of the IF data shows clearly that the bake-hardening effect in ultra-low carbon steel is entirely due to atmosphere formation, with the dislocation segment length being the main parameter affecting the IF peak amplitude. Recovery annealing experiments showed that the rearrangement of the dislocation structure lead to the elimination of the C atmosphere. 相似文献
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Role of Rare Earth in Low Sulphur Nb-Ti-Bearing Steel 总被引:2,自引:0,他引:2
The effect of rare earth on the microstructures, mechanical properties and inclusions in low sulphur Nb-Ti-bearing steel were investigated. It is shown that the transverse yield point, the traverse tensile strength and elongation of testing 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 toughness above -20℃ and it does not affect the type of microstructures which are still 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, refined and dispersed, and thus improves the distribution of inclusions. 相似文献
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Chen Lin Liu Yuyan Bao Xirong Gao Michao Zong Wei Tian Zhongliang Ren Huiping 《中国稀土学报(英文版)》2007,25(Z1):250-253
In view of fine cracks occurred on the surface of BNbRE continuous casting slabs for heavy rail in the practiced production, the effect of two factors, i. e. deformation temperature, deformation velocity, on thermo plasticity of BNbRE steel at the third brittle zone was quantitatively investigated on GLEEBLE-1500D thermal-mechanical simulator after measuring the RA-T curve of BNbRE steel. The results provide experimental data for optimizing the technology of continuous casting secondary cooling zone and avoiding the occurrence of fine surface cracks. 相似文献
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采用Gleeble-1500热/力模拟试验机进行压缩试验,研究了不同变形条件下微量稀土对T91耐热钢动态再结晶行为的影响.分析绘制了稀土加入前后实验钢的真应力-真应变曲线、再结晶-温度-时间图、再结晶图及功率耗散图,并计算了高温下实验钢的再结晶激活能.在变形温度为850~1100℃,变形速率为0.004~10 s-1变形条件下,变形温度越高和变形速率越低,动态再结晶越容易发生.稀土加入会产生固溶强化,稀土元素与碳原子发生交互作用,且在晶界处或晶界附近偏聚,使变形抗力与峰值应变均增大,再结晶激活能由354.6 kJ·mol-1提高到397.2 kJ·mol-1.另外,稀土会显著推迟再结晶发生时间,扩大再结晶的时间间隔,推迟再结晶动力学过程. 相似文献
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扩大稀土钢生产,促进稀土工业发展 总被引:1,自引:0,他引:1
论述了稀土工业是我国具有特色的优势工业,稀土工业是由稀土应用的推动而发展的,简要叙述了我国稀土钢发展道路的曲折和前景看好,进而论述了稀土钢的发展将促进我国稀土工业的发展。 相似文献