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Selection of Heat Treatment Process and Wear Mechanism of High Wear Resistant Cast Hot-Forging Die Steel

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Journal of Iron and Steel Research International 2012年第5期19卷 50-57页

作者： WEI min-xian WANG Shu-qi WANG Lan CUI Xiang-hong chen kang-min School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50--300 N at 400℃ by a pin-on-disc high temperature wear machine. The effect of heat treatment process on wear resistance was systematically studied in order to select heat treatment processes of the steel with high wear resistance. The morphology, structure and composition were analyzed using scanning electron microscopy （SEM）, X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS） ; wear mechanism was also discussed. Tribo-oxide layer was found to form on worn surfaces to reduce wear under low loads, but appear inside the matrix to increase wear under high loads. The tribo-oxides were mainly consisted of Fe3O4 and Fe2O3, FeO only appeared under a high load. Oxidative mild wear, transition of mild-severe wear in oxidative wear and extrusive wear took turns to operate with increasing the load. The wear resistance strongly depended on the selection of heat treatment processes or microstructures. It was found that bainite presented a better wear resistance than martensite plus bainite duplex structure, martensite structure was of the poorest wear resistance. The wear resistance increased with increasing austenizing temperature in the range of 920 to 1 120 ℃, then decreased at up to 1 220 ℃. As for tempering temperature and microstructure, the wear resistance increased in following order： 700℃ （tempered sorbite）, 200 ℃ （tempered martensite）, 440 to 650 ℃ （tempered troostite）. An appropriate combination of hardness, toughness, microstructural thermal stability was re- quired for a good wear resistance in high-temperature wear. The optimized heat treatment process was suggested for the cast hot-forging steel to be austenized at 1020 to 1 120 ℃, quenched in oil, then tempered at 440 to 650℃ for 2 h.

关键词： cast hot-forging die steel heat treatment process high-temperature wear mechanism wear behavior microstructure

Effect of Alloying Elements on Thermal Wear of Cast Hot-Forging Die Steels

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Journal of Iron and Steel Research International 2006年第5期13卷 53-59页

作者： WANG Shu-qi chen kang-min CUI Xiang-hong JIANG Qi-chuan HONG Bian School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 Jiangsu China School of Materials Science and Engineering Jilin University Changchun 130025 Jilin China

The effect of main alloying elements on thermal wear of cast hot-forging die steels was studied. The wear mechanism was discussed. The results show that alloying elements have significant influences on the thermal wear of cast hot-forging die steels. The wear rates decrease with an increase in chromium content from 3% to 4% and molybdenum content from 2% to 3%, respectively. With further increase of chromium and molybdenum contents, chromium slightly reduces the wear resistance and molybdenum severely deteriorates the wear resistance with high wear rate. Lower vanadium/carbon ratio （1.5-2.5） leads to a lower wear resistance with higher wear rate. With an increase in vanadium/carbon ratio, the wear resistance of the cast steel substantially increases. When vanadium/carbon ratio is 3, the wear rate reaches the lowest value. The predominant mechanism of thermal wear of cast hot-forging die steels are oxidation wear and fatigue delamination. The Fe2O3 and Fe3O4 or lumps of brittle wear debris are formed on the wear surface.

关键词： hot-forging die cast steel alloying element thermal wear mechanism

Complex Boronized Layer on the Hot-dip Aluminized Steels and Its Surface Performances

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材料热处理学报 2004年第05B期25卷 653-656页

作者： LUOXin-min LIDian-kai WANGLan chenkang-min JiangsuUniversity ZhenjiangJiangsuP.R.China

Plain carbon steels were dipped in molten aluminum bath at 720°C ±5°C and diffused for 1, 2.5 and 6 hours respectively and then boronized at 950°C for 6 hours. The oxidation, hot-corrosion and abrasion resistance behavior were examined. The experimental results showed the compounds of the aluminized layer, from the surface to the matrix, were composed of Fe2Al5 ( n -phase ) .. Fe3Al ( -phase ) and a phase. The microstructure of aluminized plus complex boronized were similar to that simplex boronized. The XRD analysis results indicated that there existed Fe2B> Fe2AlB2and Fe2Als in this kind of layer. The simplex aluminized layers still remained bright gray appearance when oxidized at 950°C, but complex boronized layer was not able to resist oxidization at the temperature. Both the layers of complex boronized and aluminized had the same anti-oxidization level in the circulative oxidization tests, and also good anti-corrosion ability in molten salt medium. Under dry abrasive conditions, wear resistance of complex boronized layer was superior to the aluminized layer.

关键词：热镀喷铝钢硼化热腐蚀磨损

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运载火箭数字化工程初步研究

宇航学报 2008年第2期29卷 718-721页

作者：张晨光陈闽慷北京宇航系统工程研究所北京100076

为适应未来航天科技发展需求,在借鉴国内外航空航天数字化研制的基础上,以我国运载火箭面临的研制需求为背景,通过体系规划、总体框架、层次结构等方面的论述,对运载火箭数字化工程进行初步研究,为运载火箭数字化研制提供技术途径。

关键词：运载火箭数字化

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来流预旋对离心压缩机级间部件性能的影响

动力工程 2007年第1期27卷 24-28,49页

作者：王企鲲陈康民上海理工大学动力工程学院上海200093

利用CFD技术,重点研究了来流周向预旋对多级离心压缩机级间弯道与回流叶栅等静止部件内气动性能的影响。结果表明:弯道内均存在不同程度的流动分离,且分离区的大小随来流周向预旋的增强而增大;降低来流周向预旋能有效地抑制弯道内流动分... 详细信息

利用CFD技术,重点研究了来流周向预旋对多级离心压缩机级间弯道与回流叶栅等静止部件内气动性能的影响。结果表明:弯道内均存在不同程度的流动分离,且分离区的大小随来流周向预旋的增强而增大;降低来流周向预旋能有效地抑制弯道内流动分离,并能使弯道出口(即回流叶栅进口)气流更趋于均匀,这有助于提高回流叶栅的气动性能;回流叶栅内的流动是非均匀、不稳定、剧烈分离的旋涡流动,沿主流方向存在着复杂的二次涡结构,这些二次流旋涡随主流经历着明显的“初生、发展、耗散、溃灭”的过程。

关键词：动力机械工程多级离心压缩机回流叶栅弯道来流周向预旋气动性能二次流

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封闭旋转型油井底流场能量变化的数值研究

动力工程 2005年第3期25卷 453-456页

作者：杨丽陈康民上海理工大学上海200093

PDC水力参数的不同综合表现为井底流场能量的变化。井底流场具有清岩和冷却切削齿的作用,同时又要保证射流不对钻头表面造成过多的磨损。针对实际PDC钻头建立了不同的流场计算模型,比较分析了流场能量的变化规律。

关键词：钻井工程 PDC钻头井底流场水力参数能量变化

CrNiNRE奥氏体耐热钢的电解活化热浸扩散渗铝研究

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材料热处理学报 2007年第1期28卷 118-122页

作者：罗新民陈康敏江苏大学材料科学与工程学院江苏镇江212013

采用表面电解活化助镀技术在渗碳炉辐射管用CrNiNRE奥氏体耐热钢表面进行了热浸扩散渗铝试验研究。应用SEM电镜和能谱分析及显微硬测试等方法分析CrNiNRE耐热钢热浸扩散渗铝层的成分、组织和形貌。试样经电解活化助镀后,在735℃铝浴中浸... 详细信息

采用表面电解活化助镀技术在渗碳炉辐射管用CrNiNRE奥氏体耐热钢表面进行了热浸扩散渗铝试验研究。应用SEM电镜和能谱分析及显微硬测试等方法分析CrNiNRE耐热钢热浸扩散渗铝层的成分、组织和形貌。试样经电解活化助镀后,在735℃铝浴中浸镀5min,获得了良好的热浸镀铝过渡层。以NH4Cl为活化剂,添加少量CeO2稀土混合物,在960℃密封扩散6h,随炉冷却,在耐热钢表面获得了结合良好的扩散渗铝层。

关键词：电解活化耐热钢辐射管奥氏体渗铝

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进口湍流对透平叶栅内部流动影响的数值研究

动力工程 2005年第3期25卷 325-330页

作者：杨宁戴韧陈康民上海理工大学动力工程学院上海200093

通过求解N S方程,分别采用Spalart Allmaras与k eps 湍流模型,对VKI低速轴流透平叶栅内部的湍流进行了数值分析。与实验结果比较,两种湍流模型计算结果与实验是一致的。叶栅流动损失的构成、分布以及计算准确性的主要因素是来流边界层... 详细信息

通过求解N S方程,分别采用Spalart Allmaras与k eps 湍流模型,对VKI低速轴流透平叶栅内部的湍流进行了数值分析。与实验结果比较,两种湍流模型计算结果与实验是一致的。叶栅流动损失的构成、分布以及计算准确性的主要因素是来流边界层状态。入口边界层是端部损失的主要来源。在高速流动条件下,叶栅损失主要是吸力面边界层径向串流及其尾迹。

关键词：动力机械工程叶栅湍流模型边界层尾迹

大型渗碳炉用CrNiNRE耐热钢辐射管的失效机理研究　　

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金属热处理 2006年第4期31卷 68-72页

作者：罗新民陈康敏潘励江苏大学材料学院江苏镇江212013

应用SEM电镜、能谱分析及X射线衍射等方法研究了高镍铬含氮和稀土的奥氏体型CrNiNRE耐热钢辐射管在长期高温渗碳中的失效机理和组织特征。结果表明,CrNiNRE钢在长期高温和单边渗碳作用下,使得M7C3碳化物持续长大,并促使奥氏体区域退缩... 详细信息

应用SEM电镜、能谱分析及X射线衍射等方法研究了高镍铬含氮和稀土的奥氏体型CrNiNRE耐热钢辐射管在长期高温渗碳中的失效机理和组织特征。结果表明,CrNiNRE钢在长期高温和单边渗碳作用下,使得M7C3碳化物持续长大,并促使奥氏体区域退缩和沿碳化物周边形成裂隙;合金元素的重新分布造成基体贫铬;管内壁氧的侵入形成氧化空洞和疏松;这些因素的综合作用导致构件最终贯通穿孔而失效。

关键词：奥氏体耐热钢辐射管渗碳 M7C3碳化物失效