新型车架大梁钢涂装工艺研究——绿色免酸洗EPS表面处理钢初探

通过对热轧钢板和绿色免酸洗表面处理钢（简称EPS钢）的工艺、耐腐蚀性研究,分析了EPS钢具备除锈等级高,除锈后钢材表面质晕好的优点,提出了EPS钢可用于车架大梁钢等零部件,值得推广和应用。     

Finite Element Calculation of the Flexural Stiffness of Corroded RC Eccentric Compressive Members

A finite element calculation model of corroded RC eccentric compressive members was build using finite element software ANSYS. The model considers the decline of mechanical properties and the effective section of a corroded steel bar, as well as the deterioration of bond character between corroded reinforcement and concrete. The reliability of the finite element model was evaluated by comparing the results of the finite element calculation with the data from experiments. Based on the finite element analysis results, the influence of corrosion degree, the diameter change of the longitudinal reinforcing bars and the spacing change of stirrups on the flexural stiffness were calculated and analyzed.     

钢筋混凝土桥梁的耐久性

在分析影响钢筋混凝土桥梁耐久性因素的基础上，介绍了提高钢筋混凝土桥梁耐久性的新方法，以期引起桥梁工作者对桥梁耐久性的重视。     

摩托车减震器底筒锈蚀原因及控制

对于摩托车减震器底筒受潮后锈蚀,一般都认为是涂装工艺过程不合理或涂料选择不当引起的。经过无数次反复的试验后发现,底筒受潮锈蚀与铝合金材料夹杂物及铸造工艺控制有直接关系。     

Predictive analyses of the integrity of corroded pipelines based on concepts of structural reliability and Bayesian inference

In this paper, structural reliability concepts are used in conjunction with limit state functions proposed in the Recommended Practice DNV-RP-F101 (2010) to evaluate the probability of failure of corroded pipelines during their lifetimes. The model takes into account the natural spread of material properties, geometric and operational parameters, and the uncertainties associated with the sizing of eventual corrosion defects. Bayesian reliability concepts are used to estimate the evolution of a pre-defined distribution of defects obtained, for instance, from an inspection campaign. By comparing the predicted probability of failure with the reliability acceptance criteria, the operator can schedule defect repairs and establish inspection intervals with more confidence. This proposed methodology can provide the basis to develop a risk based maintenance strategy of pipeline systems.     

Effects of adhesive type on the mechanical properties of adhesive joints between polyurethane top coats and polyurethane-based adhesives after accelerated atmospheric ageing

The performance of a sealed stainless steel bracket system, adhesively bonded with two polyurethane-based adhesives (flexible adhesive, stiff adhesive) onto a marine polyurethane top coat, is investigated. The investigated joint connections on the coatings exhibited a high mechanical stability even after accelerated ageing (salt spray exposure, cyclic temperature variations, high relative humidity). The aged joints retained up to 81% of their tensile strength and up to 92% of their lap-shear strength. The torsional rigidity of the adhesive joint exceeded the required clamping torque of the designed bolt. A cyclical lifetime of >9·10⁶ load cycles was estimated. Effects of cyclic ageing on the creep performance of the adhesive joint were found to be insignificant. Under tensile loads, the joints with stiff adhesive material exhibited a linear-elastic performance without the capability to deform prior to failure. The joints with the flexible adhesive material, in contrast, exhibited a behavior typically for ductile materials featuring a pronounced yield plateau prior to failure. Failure loads were higher, and displacement was notably lower, for the joints with stiff adhesive material. All joint connections met the requirements for a safety factor for the design for marine applications (11.6 for the flexible adhesive; 14.3 for the stiff adhesive). When the flexible adhesive is applied, the cohesive strength of the adhesive material is the limiting design factor. When the stiff adhesive is utilized, the load carrying capacity is higher, and the interface between priming coat and steel substrate is the limiting design area of the joints. The strength utilization of the adhesive materials depended on the particular structure of the entire joint configuration, particularly on the interface between steel substrate and the coating material. A number of assessment factors, namely stress limit factor, coating adhesion factor and safety factor, are introduced and discussed for tensile and shear loads.     

AZ91与AM60腐蚀性能比较研究

文章利用浸泡失重法和动电位测极化曲线法,研究了铸造镁合金AZ91和AM60在不同介质中的腐蚀性能,并比较不同热处理工艺对镁合金腐蚀性能的影响。     

严寒地区桥梁在盐冻环境下的耐久性技术研究

吉林省位于我国东北地区中部,是典型的季节性冰冻地区,冬季漫长寒冷。桥梁所处的野外自然条件恶劣,且除雪时还会大量使用除冰盐,这对桥梁耐久性会造成极大影响。对吉林省境内桥梁结构普遍存在的病害进行总结,提出在冻融和氯盐侵蚀共同作用时能够提高桥梁耐久性的技术措施。研究的成果将为在今后的设计、施工、养护提供数据资料和具体的技术建议,从而提高结构耐久性,延长桥梁构造物的使用寿命。     

铜合金腐蚀的影响因素及研究状况

本文先叙述了铜合金的应用领域,并指出其腐蚀行为研究的必要性。然后分别阐述了不同的影响因素对铜合金的腐蚀行为及研究状况的影响,其影响因素主要就铜合金自身的组织成分、铜合金的热处理及所处环境条件这三方面进行阐述。最后对铜合金的腐蚀规律进行了总结与展望。     

Marine field test for steel reinforcement embedded in mortar: Coupled influence of the environmental conditions on corrosion

This paper studied the environmental conditions and corrosion behaviour of mortar samples at two different marine tidal zones and investigated the correlation among the environmental conditions, corrosion rates, and corrosion products. From the experimental results, the concrete structure damage is a function of numerous correlated factors such as the temperature, humidity, and corrosion products. The chloride penetration rate increased by 15% when the humidity increased by 10% and temperature increased 4 °C. Chloride content is the main factor intensifying the reinforcement corrosion. Although the high temperature, humidity, and chloride concentration aggravate the early corrosion of reinforcement, the role of resultant corrosion products shows more important in the developing stage of corrosion damage. The resultant corrosion products affect further corrosion persistence in a complex way, because in some cases, corrosion products-caused cracks will promote corrosion, while in others, corrosion is reduced by sealing the pores with products.