不锈钢在模具制造中的应用

介绍了奥氏体不锈钢、马氏体不锈钢、沉淀硬化型不锈钢在热作模具、无磁冷作模具和塑料模具中的应用。并简要讲解了几种典型不锈钢的性能、应用及热处理工艺。     

保温式多功能离子化学热处理的装置、工艺和应用

本文简要介绍了青岛科技大学等离子体表面技术研究所最新研制的保温式多功能离子化学热处理装置,以及用这套装置研发出的离子化学热处理新工艺,其中包括离子软氮化+后氧化复合处理和奥氏体不锈钢低温离子表面硬化处理等。     

冷轧不锈钢板材实验设备介绍

介绍了宝钢集团某公司技术中心实验工场中的冷轧,退火设备特点,这些设备可为不锈钢新产品研发及冷轧大生产提供切实可靠的生产工艺参数.     

全国首家热处理质检中心落户天津

日前，全国首个中国热处理行业协会质量检测中心落户天津市热处理研究所有限公司。 面对经济危机对国内制造业的冲击，天津热处理研究所公司在加强科技创新和新产品研发力度的同时，积极开拓市场，加大产品的市场占有率，使公司的市场份额占有率达到90％。     

数控机床用PEMFC热处理不锈钢双极板的热机械分析

在试验基础上,分析了不锈钢与石墨接触电阻在不同热处理温度下随热处理时间的变化关系,并建立了质子交换膜燃料电池热处理不锈钢双极板的热机械模型.结果表明:在同一温度下,不锈钢与石墨接触电阻随热处理时间的变化而变化;800℃的高温热处理的接触电阻比900℃的高温热处理的接触电阻明显低得多.热处理不锈钢双极板的最大等效应力和位移都足够小,这对于质子交换膜燃料电池十分重要,必须使其足够小才能使双极板准确分离阳极和阴极的氢气和氧气.     

双相不锈钢特性及热轧中板生产要点

双相不锈钢兼有奥氏体不锈钢和铁素体不锈钢的优点,即具有优良的力学性能、耐蚀性,以及良好的焊接性而得到迅速发展。本文介绍了双相不锈钢的发展情况,其优良的耐腐蚀性能和力学性能,以及生产中钢板边裂和热处理σ相的控制要点。     

马氏体不锈钢的光亮热处理

简要介绍了马氏体不锈钢真空热处理和可挖气氛热处理两种光亮热处理的特点及其现场应用,生产实践证明,马氏不锈钢采用光亮热处理能最大限度地发挥材料和工艺技术优势。     

抗菌热处理对SUSXM7含Cu不锈钢冷加工性能的影响

研究了抗菌热处理前后SUSXM7含Cu奥氏体不锈钢的力学性能,并与通用奥氏体不锈钢SUS304进行了对比.结果表明:SUSXM7含铜不锈钢的加工硬化指数低于SUS304不锈钢,塑性应变比高于SUS304不锈钢,两种材料的杯突深度基本接近,SUSXM7含铜不锈钢的冷加工成形性能优于SUS304不锈钢.抗菌热处理后,SUSXM7含铜不锈钢的加工硬化指数、塑性应变比、杯突深度没有太大变化,抗菌热处理对SUSXM7含铜不锈钢的冷加工成形性能没有太大影响.SUSXM7含铜不锈钢可以在抗菌热处理前进行冷加工成形,也可以在抗菌热处理后再进行冷加工成形.     

国内首条在线辊底式不锈钢线卷热处理线在太钢正式投产

正据悉,由国机集团中国联合工程有限公司研发的国内首条在线辊底式不锈钢线卷固溶退火热处理生产线在太钢集团正式批量投产。不锈钢线卷在轧制下线后,温度仍会达到650～800℃,传统工艺必须等待环冷再重新热处理,单卷工艺处理需1天时间,生产效率低、能耗过高,且需配置离线堆料场地,严重制约企业对节能减耗、降本增效的推进。     

真空热处理对冷喷涂304不锈钢涂层弹性模量的影响

采用光学显微镜、电子探针、三点弯曲试验和冷喷涂单边涂层弹性模量理论模型等方法,研究了真空热处理对冷喷涂304不锈钢涂层弹性模量的影响。结果表明：在热处理过程中,304不锈钢涂层内部的金属原子发生扩散、局部粒子界面发生融合,使粒子间结合力和涂层力学性能得以改善;同时涂层中的氧元素也发生扩散形成团聚体,分布于粒子边界处,使得涂层的弹性模量降低。热处理温度低于500℃时,304不锈钢涂层的弹性模量和等效抗弯刚度变化不大,与冷喷态涂层相当;当热处理温度超过500℃后,304不锈钢涂层的弹性模量和等效抗弯刚度随着热处理温度的升高迅速降低;在热处理温度相同的情况下,304不锈钢涂层的弹性模量和等效抗弯刚度随着热处理时间的增加而降低。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.