硬质合金YG15的热冲击行为研究

研究了硬质合金ＹＧ１５的热冲击行为。结果表明,热冲击裂纹的形成存在孕育期,热冲击曲线（σｒｂ－ｔ）上热冲击残留强度随热冲击温度的升高表现为先降后升的规律。扫描电镜观察表明,在试样的亚表层下存在孔洞,热冲击断口由沿晶和穿晶组成。     

油井管钢氢致开裂门槛值研究

四种高强度油井管钢动态及氢时，进入试样的可扩散氢含量ｃ０和充氢电流ｉ成正比，而氢致断裂门榄应力σｃ与名义屈服强度σｔ之比和ｌｎｃ０成正比，即σｃ／σｔ＝Ａ－Ｂｌｎｃ０，测量了四种钢在Ｈ２Ｓ中浸泡进入试样的Ｃ０，求出相应的ｉｃ，用ｉｃ充氢时同的门槛应力σｃ（Ｈ）／σｔ和Ｈ２Ｓ中应力腐蚀门槛应力σＣ（Ｈ２Ｓ）／σｔ相一致，这表明，可用特定电流下的动态充氢来代替Ｈ２Ｓ应力腐蚀。     

C-Mn钢焊接接头的解理断裂行为的研究

测定不同φ（焊缝）的C－Mn钢焊接接头Charpy-V冲击试样、COD裂纹试样的低温断裂参量，φ（焊缝）小于一定值时，解理裂纹起裂于母材各区，韧性用σf/σy较小的分散带表征；当φ（焊缝）大于一定值时，解理裂纹起到焊缝粗晶区，韧性用相应的σf/σy较窄的分散带表征。焊接接头的解理断裂由脆性相开裂形成微裂纹，在外加主应力达到解理断裂应力σf时导致解理断裂。     

粘结层表面处理对热障涂层残余应力及热冲击寿命的影响

采用真空电弧离子镀技术在二代单晶高温合金DD32表面制备NiCoCrAlYHf（HY5）金属粘结层，通过振动光饰、吹砂及振动光饰和吹砂3种不同的表面处理方法改变粘结层表面状态，利用电子束物理气相沉积（EB-PVD）技术制备氧化钇部分稳定氧化锆（7~8YSZ）陶瓷层。借助扫描电子显微镜（SEM）、电子探针（EPMA）、光激发荧光压电光谱（PLPS）等分析手段，研究1100 ℃热冲击过程中热障涂层界面结构、成分及残余应力的演变。结果表明:表面处理能够改善粘结层表面形貌，其对TGO层残余应力大小及热冲击寿命存在影响；未处理试样应力水平高于经过表面处理的热障涂层试样，并且随着热冲击次数的增加未处理试样残余应力涨幅更大；经过表面处理后试样热冲击寿命提高，其中经过振动光饰处理的试样提升最为显著；粘结层表面吹砂处理会造成砂粒进入粘结层表层某些部位，TGO层局部过度生长，造成应力集中，从而涂层寿命低于振动光饰处理试样。     

陶瓷注射成型脱脂方法对ZrO2陶瓷性能的影响

利用超临界CO2流体、溶剂和热处理3种方法对ZrO2陶瓷注射成型坯体进行脱脂,并对试样进行了一系列的性能测试.实验结果显示,脱脂方法对陶瓷性能有较大的影响.超临界流体脱脂克服了热脱脂的开裂、变形等各种缺陷,使烧结件获得较好的力学性能,平均抗弯强度σ为1074MPa，Weibull模数m达到18．93，高于利用溶剂脱脂的烧结件（σ=1038．4MPa，m=13．28）和热脱脂烧结件（σ=983．5MPa，m=7．59）。此外，超临界CO2流体脱脂、溶剂脱脂可使陶瓷注射成型脱脂时间大大减少，脱脂过程约缩短到热脱脂的1／20。     

铬白口铸铁—钢复合结构的组织与性能

采用铸造方法，将不同直径的４５钢钢筋包覆在铬白口铸铁（低铬和中铬）芯部，研究了所得复合试样的组织与性能，结果表明，选用较大直径比（钢筋直径／试样直径）并经适当热处理，可获得较理想的综合性能，外层铬白口铸铁的硬度可达ＨＲＣ６１．５￣６４．５，复合试样的抗弯强度可达σＷ＝７００￣１０００ＭＰａ，比单－铬白口铸铁提高４０￣４５％。     

介稳奥氏体锰钢应变诱发马氏体相变的热图研究

介稳奥氏体锰钢应变诱发马氏体相变的热图研究张福成，郑炀曾，雷廷权（燕山大学）（哈尔滨工业大学）１前言金属变形过程中绝大部分应变能以热的形式释放￣［１１］。红外热图方法已成功地应用了金属变形温升的研究￣［２，３］，奥氏体向马氏体转变是放热过程，试样上发...     

贝氏体球墨铸铁球磨机衬板的可行性研究

采用热开箱继以受控冷却的模拟等温淬火热处理方法，研究了ＣＵ—ＭＯ合金球墨铸铁用于制作球磨机衬板的可行性。采用本工艺处理的冲击试样，其基体组织为下贝氏体加部分马氏体及少量残余奥氏体，冲击值（无缺口试样）大于２０Ｊ／ｃｍ２，硬度值大于ＨＲＣ４５，使用性能优于高锰钢和中锰球墨铸铁。     

强化方式对HRB400E钢筋使用性能的影响

对比分析了TMCP非微合金化（1#试样）和0.03%VN微合金化（2#试样）两种工艺生产的HRB400E钢筋的焊接和抗震性能差异。主要对焊接热影响区焊缝处的显微硬度和冲击功以及焊接强度作了对比试验，还对衡量抗震性能的强屈比指标进行了对比分析。结果表明，1#试样HV10整体硬度值高于2#试样大约20～30，，硬度最大处均在焊缝区，1#试样从焊缝中心向外的硬度呈现明显降低趋势，这主要是因为其焊缝区域产生了贝氏体；此外，1#试样焊接热影响区的韧-脆转变温度在5 ℃左右，2#试样则在10 ℃左右；1#试样的强屈比范围是1.30～1.35，2#试样为1.32～1.35，都满足了抗震钢筋的要求。     

焊后热处理对双相钢SAF2507带极堆焊层组织与性能的影响

通过试验对比分析了超级双相钢SAF2507带极堆焊层焊态和焊后热处理试样的力学性能和耐点腐蚀性能,探讨了经焊后热处理后堆焊层中σ相的析出行为。结果表明,经焊后热处理的堆焊层铁素体相上析出了弥散分布的有害相σ相,σ相硬而脆,严重降低堆焊试样的低温(-40℃)冲击性能,同时σ相周围的贫铬贫钼区容易发生点蚀从而导致带极堆焊层耐腐蚀性能变差。因此SAF2507钢带极堆焊层应避免在600~900℃进行焊后热处理。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

RHEOLOGY FEATURE OF SIMPLE METAL MELT

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Microstructures and Mechanical Properties of a Newly Developed Austenitic Heat Resistant Steel

The effect of heat treatment on the microstructures and mechanical properties of a newly developed austenitic heat resistant steel(named as T8 alloy) for ultra-supercritical applications have been studied. Results show that the main phases in the alloy after solution treatment are γ and primary MX. Subsequent aging treatment causes the precipitation of M_(23)C_6 carbides along the grain boundaries and a small number of nanoscale MX inside the grains. In addition, with increasing the aging temperature and time, the morphology of M_(23)C_6 carbides changes from semi-continuous chain to continuous network.Compared with a commercial HR3C alloy, T8 alloy has comparable tensile strength, but higher stress rupture strength. The dominant cracking mechanism of the alloy during tensile test at room temperature is transgranular, while at high temperature, intergranular cracking becomes the main cracking mode, which may be caused by the precipitation of continuous M_(23)C_6 carbides along the grain boundaries. Typical intergranular cracking is the dominant cracking mode of the alloy at all stress rupture tests.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.