Cr12MoV钢硫氮碳共渗层摩擦磨损特性研究

探讨了Ｃｒ１２ＭｏＶ钢硫氮碳共渗层中硫的渗入深度及渗层表面状态对摩擦系数和耐磨性的影响。     

35CrMo钢离子氮化与激光相变硬化复合处理及真耐磨性的研究

介绍了３５ＣｒＭｏ钢氮化加激光相变复合处理后组织及硬度分布的规律，并在各种工艺和材料条件下进行了滑动磨粒磨损试验。结果证明：复合处理的淬硬层深度大于非氮化激光处理的硬化层。在滑动磨粒磨损条件下，与３５ＣｒＭｏ钢氮化或激光相变硬化相比，复合工艺可获得更好的耐磨性，基本与ＧＣｒ１５钢淬火、低温回火相当。     

新型高温用渗碳轴承钢的接触疲劳寿命

研究了新型高温用渗碳轴承钢（１０Ｃｒ４Ｎｉ４Ｍｏ４Ｖ）及高温用完全化轴承钢（Ｃｒ４Ｍｏ４Ｖ）的接触疲劳寿命及其组织。结果表明，１０Ｃｒ４ＮｉＭｏ４Ｖ钢的接触疲劳寿命高于Ｃｒ４Ｍｏ４Ｖ钢，１０Ｃｒ４Ｎｉ４Ｍｏ４Ｖ钢渗碳层中存在较高的残留压应力，渗层组织中碳化物细小且呈均匀弥散分布。     

离子硫氮复合渗42CrMo钢的耐磨性和抗咬合性研究

研究了离子硫氮复合渗对42CrMo钢的耐磨性和抗咬合性的影响。数据表明，与42CrMo钢调质态和单一离子渗氮工艺状态相比，该钢经离子硫氮复合渗处理后可明显提高钢的耐磨性和抗咬合性。通过对渗层的组织结构分析，探讨了硫氮复合渗层对提高42CrMo钢的耐磨性和抗咬合性的作用机理。     

PIC—D型防渗碳剂的研制

采用反应防渗，致密层覆盖隔绝气氛防渗及氧化还原防渗机理，开发研制的ＰＩＣ－Ｄ型防渗碳剂，成本低廉价，无毒，无臭，无公害。具有良好的低、高温性能，适用于２０ＣｒＭｎＴｉ钢以及２０Ｃｒ钢、３０ＣｒＭｎＴｉ钢、２０钢等常用渗碳钢的防渗处理，对其它渗碳及碳氮共渗钢也有一定的防渗效果。     

38CrMoAl的切削优化的选择

３８ＣｒＭｏＡｌ的切削优化的选择佳木斯工学院孟然，王贵成石油生产中广泛应用的抽油泵其泵套材料为３８ＣｒＭｏＡｌ，碳氮共渗层≥１ｍｍ，淬火硬度ＨＲＣ５６—６０。泵套磨损到一定程度则更换新泵套及柱塞。每台泵２８节泵套．每节价值７８元（１９８８年）．如能对...     

变质M2高速钢稀土离子硫碳氮共渗研究

对Y-K-Na复合变质的M2高速钢进行离子硫碳氮共渗和稀土离子硫碳氮共渗处理,研究稀土元素对复合变质M2高速钢离子硫碳氮共渗组织和性能的影响。试验结果表明:稀土元素改善变质M2高速钢渗层组织,提高表面硬度,使渗层硬度梯度平缓,可有效地提高其抗摩擦磨损的能力。     

38CrMoAl钢等离子体源离子注入表面改性研究

对３８ＣｒＭｏＡｌ钢等离子体源氮离子注入层的氮浓度俄歇部面分布，显微硬度和摩擦性能进行了研究。结果表明，注入层的显微硬度和摩擦性能得到明显改善。     

合金化渗氮的组织性能与应用

针对合金化涌氮的组织性能进行了研究，研究结果表明，合金化渗氮可形成高硬度，低脆性和致密的渗层；４０Ｃｒ钢合金化参氮后的接触疲劳强度与常规气体氮碳共渗相比提高８３．３３％。     

管模用钢21CrMo10材料的研究

本文论述了大型离心铸造管模用钢２１ＣｒＭｏ１０的合金成分，组织，性能及热处理工艺同管模另一种钢３０ＣｒＭｏ的比较。通过对比研究结果表明２１ＣｒＭｏ１０钢和模的性能明显优于３０ＣｒＭｏ材质。     

Influence of multiple nitriding on the case hardening of H13 tool steel: experimental and numerical investigation

Controlled gas nitriding represents one of the most important factors in enhancing the service life of AISI H13 steel dies used for the hot extrusion of aluminum alloys. Such surface-hardening treatment is used repeatedly to re-harden the die surface, which has been exposed to high temperature and abrasion by extruding the aluminum alloy, resulting in the wearing away of the existing nitride layer. Therefore, after certain extrusion cycles, dies require re-nitriding. In the present work, the influence of repeated nitriding on AISI H13 steel is studied. Single-, double-, and triple-nitrided samples, treated under controlled two-stage gas nitriding process, have been included in the study to evaluate their nitride layer morphology, hardness, case depth, and quality. Both experimental and numerical results are presented and compared. In the experimental part, the nitride layers are characterized using different techniques including optical microscopy, scanning electron microscopy, X-ray diffraction analysis, microhardness analysis, and energy-dispersive spectrometry technique. A sequentially coupled heat diffusion analysis of re-nitriding treatments are also conducted numerically using finite element code, ABAQUS. The numerically predicted results are in close agreement with experimental results in terms of nitride layer growth and nitrogen concentration distribution in the diffusion zone. The experimental results reveal that multiple-nitriding treatment on H13 steel has a significant effect on compound layer thickness and its phases, diffusion zone depth and its microstructure, hardness–depth profile, and nitride case depth. It was found that excessive cumulative nitriding time during multiple-nitriding treatment results in greater nitride depth and a significant increase in hardness with deeper effect due to the dense and deeper precipitation of nitrides in the diffusion zone. Multiple-nitrided samples show oxidation and porosity in the near-surface part of the nitrided layer due to the interaction of iron with oxygen of the air upon decomposition of iron nitrides in the compound layer during re-nitriding. This results in reduced toughness and hardness in the near-surface part of the nitride layers.     

稀土元素对SnAgCu焊点内部组织的影响机制

随着人们环保意识的逐渐增强,新型无铅钎料的研究成为电子工业中的研究热点,而稀土元素的添加可以显著改善钎料的性能,基于含稀土Ce无铅钎料的钎焊试验,采用扫描电镜和能谱仪研究稀土元素Ce对SnAgCu焊点内部组织的影响机制。结果表明,稀土元素在SnAgCu焊点内部以CeSn3的形式存在,且稀土相形态各异。采用化学亲和力来表征稀土元素Ce与Sn、Ag、Cu之间的内在联系,从理论上证明Ce的“亲Sn性”。采用乌尔夫原理研究稀土元素的吸附现象,解释稀土元素Ce对SnAgCu焊点内部金属间化合物的细化作用。由SnAgCuCe焊点组织分析,发现基体组织中颗粒尺寸大小排序为CeSn3>Cu6Sn5>Ag3Sn,从理论上证明纳米Ag3Sn颗粒在SnAgCuCe焊点强化中发挥着主要的作用。研究结果可以为新型无铅钎料的研究提供理论支撑。     

The application of convergent beam electron diffraction (CBED) analysis on transformation‐induced plasticity (TRIP) steels

Convergent beam electron diffraction (CBED) in transmission electron microscopy (TEM) was applied to determine local carbon concentrations in low‐carbon transformation‐induced plasticity (TRIP) steels. High‐order Laue‐zone (HOLZ) lines were experimentally obtained for comparison with simulation results. A new procedure for calculating carbon content is thus proposed. Retained austenite (RA) is classified into three types by morphology; the relationship between the carbon content and the corresponding RA morphology is discussed based on CBED results. Furthermore, results of X‐Ray diffractometry measurements are also used for comparison.     

Characterization of the near-surface layers of carbon steels modified by interaction with intense pulsed plasma beams: scanning electron microscopy investigations

Modification of materials is a wide area in materials science, especially surface modification. To investigate the results of the modification process, treated and nontreated samples were compared. Intense plasma pulses of argon or nitrogen were used to irradiate the carbon steels. In all samples, the near‐surface layer was melted. Results of scanning electron microscopy investigations of the surface morphology and cross‐sections, as well as the results of tribological tests, are presented. The obtained results allowed us to draw conclusions about changes in material properties and to propose subsequent studies using other investigation techniques.     

Structure and tribological characteristics of steel under melting by plasma flow and simultaneous Mo and W alloying

New findings of studies of the structural, tribological, and physicomechanical characteristics of structural steel 40Kh treated by plasma flow under melting accompanied by either tungsten or molybdenum alloying are presented. Rutherford back-scattering of ions, scanning electron microscopy (with microanalysis), X-ray fluorescent spectral analysis, X-ray phase analysis, wear-resistance tests, measurement of the coefficient of friction, and transmitting electron microscopy with diffraction are the basic research methods. It is found experimentally that a thin layer 5 μm thick saturated with nitrogen and an alloying element (Mo or W) with regularly arranged crystallites arises on the steel 40Kh surface. The crystallites in this layer have a needle- and ribbon-shaped structure. A deeper layer located about 40 μm thick consists of micro- and nanosized grains. Friction and wear studies of the plasma-flow treated (melt) samples show the steel wear resistance to increase 2–2.5 times and the coefficient of friction to decrease from 0.4–0.5 to 0.10–0.15 compared to the untreated samples.     

电沉积稀土改性陶瓷涂层磨损性能研究

探讨了在电火花加工机床上沉积碳化钛金属陶瓷涂层方法,利用TiC,WC,Mo,N i粉未添加不同比例稀土元素在高压下压制并烧结了试验电极,在45#钢表面沉积了不同稀土含量的TiC陶瓷涂层,并用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计、环块式磨损试验机对涂层组成、组织形态进行、硬度及摩擦学性能分别进行了研究,并结合试验结果进行了理论分析。试验结果表明:用电火花放电法可沉积TiC陶瓷涂层,涂层中加入质量分数为0.5%的氧化镧后,涂层的耐磨性能较未加稀土涂层提高了3倍,摩擦因数减少10%,而加入过多的稀土镧氧化物则不利于涂层组织性能及耐磨性能的改善。稀土氧化镧对涂层的组织有改善作用,加入适量的稀土元素使得涂层致密性提高,减少涂层中的缺陷,涂层表面呈多孔结构特性。     

稀土对H13钢在盐浴氮化中的影响

研究了稀土对Ｈ１３钢在盐浴氮化中的影响。对Ｈ１３钢进行低温无毒硫氮碳共渗,在这基础上加入稀土元素,实验结果表明,稀土元素的加入可加速盐浴氮化的过程,具有催渗效果,并能改善其性能,满足模具盐浴氮化的技术要求,具有较好的经济效益和社会效益     

SnAgCu/SnAgCuCe焊点的显微组织与性能

针对SnAgCu和SnAgCuCe两种无铅焊点,研究焊点内部组织、力学性能及热疲劳特性。研究结果表明,稀土元素Ce的加入可以提高焊点的力学性能,稀土元素的添加可以使SnAgCu焊点拉伸力提高近12.7%。稀土元素的添加细化SnAgCu基体组织,同时减小金属间化合物颗粒(Cu6Sn5和Ag3Sn)的尺寸,这是SnAgCuCe焊点力学性能提高的主要原因。拉伸断裂后的扫描电镜分析表明,两种焊点的断裂呈现明显的韧性断裂特征。另外在温度循环载荷下,稀土元素可以显著提高SnAgCu焊点的疲劳寿命。基于有限元模拟发现SnAgCuCe的抗蠕变性能显著高于SnAgCu焊点。     

The Role of Cerium in the Resistance of an MoS2-Containing Composite Brush Plating Layer to Humid Atmosphere

MoS₂ is an excellent solid lubricant widely used for reducing friction. However, moisture is very harmful to its solid lubrication property because MoS₂ is easily oxidized to form Mo⁶⁺ and S⁶⁺ in a humid atmosphere. In order to improve its oxidation resistance, a study on the role of a rare earth element Ce in the resistance of a Ni-Cu-P/Mo₂ brush plating layer to the humid atmosphere was carried out. It was found that cerium can effectively stabilize the solid lubrication property of MoS₂ due to its preferential adsorption on the surface of MoS₂ particles, the adsorbed layer serving as a barrier to oxidation. This study shows that the rare earth element Ce can be deposited from a water plating solution.     

Anand Parameters Determination for SnAgCu Solder Bearing Micro-amounts Rare Earth Ce

SnAgCu solder system with the addition of rare earth Ce,which has better thermo-mechanical properties compared to those of SnPb solder,is regarded as one of the promising candidates for electronic assembly.Moreover,the SnAgCuCe solder alloys can provide good quality joints with Cu substrates.However,there is few report of the constitutive model for SnAgCu solder beating micro-amounts rare earth Ce.In this paper,the unified viscoplastic constitutive model,Anand equations,is used to represent the inelastic deformation behavior for SnAgCu and SnAgCuCe solders.In order to obtain the acquired data for the fitting of the material parameters of this unified model,a series of experiments of constant strain rate test were conducted under isothermal conditions at different temperatures.The Anand parameters of the constitutive equations for SnAgCu and SnAgCuCe solder were determined from separated constitutive relations and experimental results.Nonlinear least-square fitting was selected to determine the model constants.And the simulated results were then compared with experimental measurements of the stress-inelastic strain curves:excellent agreement was found.The model accurately predicted the overall trend of steady-state stress-strain behavior of SnAgCu and SnAgCuCe solders for the temperature ranges from 25℃ to 150℃,and the strain rate ranges from 0.01 s-1 to 0.001 s-1.It is concluded that the Anand model can be applied for representing the inelastic deformation behavior of solders at high homologous temperature and can be recommended for finite element simulation of the stress-strain response of lead free soldered joints.Based on the Anand model,the investigations of thermo-mechanical of SnAgCu and SnAgCuCe soldered joints in fine pitch quad flat package by finite element code were done under thermal cyclic loading,it is found that the reliability of SnAgCu soldered joints can be improved remarkably with addition of rare earth Ce.The results may provide a theory guide for developing constitutive model for lead-free solders.