氢致裂纹试验及数值模拟技术国内外研究现状（1）

对氢致裂纹产生机制、影响因素、试验技术及数值模拟技术的国内外研究状况进行了综述,并对存在的问题进行了分析,认为在氢致裂纹试验技术及数值模拟技术等方面仍需进一步的研究 。     

Stress corrosion behavior of pipeline steel(X52)welded joint

The resistance of pipeline steel joint welded by submerged arc welding to stress corrosion cracking (SCC) at its different regions in boiling mixed nitrate solution and in H_2S saturated solution at room temperature is examined by the constant-load tension method. The result shows that when tested in nitrate, the weld metal may be the weakest link of the joint if the welding material doesn't match well. The resistance to SCC of the joint in H_2S is very low, especially at the bond and coarse grain zone and is closely dependent on the metallurgical quality of base metal.     

The influence of a corrosive wood-cutting environment on the mechanical properties of hardmetal tools

The influence of a corrosive wood-cutting environment on the strength of hardmetals and on their behaviour under static loading conditions has been investigated. Two commercial hardmetals were tested, which differed in hard phase composition. The results show exposure to this environment to have a highly detrimental influence on the strength of both hardmetals investigated, due to localised corrosive attack which results in the formation of stress raisers. The relative loss in strength as a function of corrosion time is the same for both hardmetals. However, the performance of the two grades differ significantly when a static load is applied in this corrosive environment: the strength of the WC-Co grade remains unaffected by the applied load, while the grade containing a mixed carbide phase exhibits stress corrosion cracking which results in a further reduction in strength.     

显微组织对管线钢硫化物应力腐蚀开裂的影响

研究了不同显微组织管线钢的抗硫化物应力腐蚀开裂（SSCC）行为,结果表明,细小针状铁素体为主的显微组织抗SSCC性能最佳,超细铁素体的显微组织次之,（铁素体 珠光体）的显微组织最差,分析表明,氢脆是高强度管线钢在SSCC中的主要破坏形式。针状铁素体为主的显微组织,其内部高密度缠结位错和弥散析出的碳氮化物起到了强烈的氢陷阱作用,表现出最佳的抗SSCC性能。     

Environmental etch performance, and scratch and mar of automotive clearcoats

Environmental etch damage to automotive coatings, and scratch and mar of these coatings are an important element of customer satisfaction as well as a significant warranty repair consideration for automotive companies. The conditions that result in environmental etch are examined and a laboratory test proposed. Data from this test are compared to automotive hoods exposed in Florida. The performance of various crosslinking chemistries is discussed and the requirements for improved environmental etch are outlined. Scratch and mar performance of these systems is also reviewed. We have found that coatings respond to physical stress by elastic recovery, by plastic flow and by brittle fracture. Classifying types of damage in this way is important for understanding the chemistry needed for improved scratch and mar of coatings.     

Conversion of light paraffins for preparing small olefins over ZSM-5 zeolites

The conversion of C₃-C₉ paraffins to small olefins over ZSM-5 zeolite is investigated. The small olefins are primary products and are usually converted into other more stable secondary products such as aromatics on the ZSM-5 zeolites. Thermally treated HZSM-5, K/HZSM-5 and Ba/HZSM-5 catalysts were developed and favourable oxidative conditions were introduced for the conversion process to maximize selective conversion of light paraffins to small olefins at the relatively low temperature of 873 K. The role of K and Ba is to minimize bimolecular hydrogen transfer reactions and enhance the dehydrogenation activity of the catalysts. Meanwhile, the oxygen in the gas phase is effective to improve the olefin selectivity and yield. C₂-C₄ olefin selectivities of 70.4 and 66.8% have been obtained for propane andn-hexane feed-stocks, respectively, at a temperature of 873 K.     

Analysis of failed nuclear plant components

Argonne National Laboratory has conducted analyses of failed components from nuclear power- gener-ating stations since 1974. The considerations involved in working with and analyzing radioactive compo-nents are reviewed here, and the decontamination of these components is discussed. Analyses of four failed components from nuclear plants are then described to illustrate the kinds of failures seen in serv-ice. The failures discussed are (1) intergranular stress- corrosion cracking of core spray injection piping in a boiling water reactor, (2) failure of canopy seal welds in adapter tube assemblies in the control rod drive head of a pressurized water reactor, (3) thermal fatigue of a recirculation pump shaft in a boiling water reactor, and (4) failure of pump seal wear rings by nickel leaching in a boiling water reactor. Work supported by Commonwealth Edison Company under ACK 85026.     

HP耐热钢裂解炉管服役弱化的组织特征及其成因

在分析测试服役HP耐热钢裂解炉管的基础上,探讨了使用过程中炉管内壁材质的弱化机制、结果表明,炉管内壁亚表层贫碳化物区及内部渗碳区的形成及加深主要与表面氧化层的剥落和重建、晶间氧化区的形成、碳及合金元素在基体中的扩散速度以及形成碳化物的临界碳浓度cmax密切相关;丝状催化焦炭的形成与发展促进了炉管内壁组织弱化,而非催化气相焦炭的沉积在一定程度上抑制了材料的弱化;反复的结焦和清焦是促使炉管内壁材质弱化的主要原因.     

磷系列新结构环保型阻燃聚酯研究进展

聚酯(PET)具有良好的物理性能,耐摩擦,绝缘性好,冲击强度高,尺寸稳定性好,吸湿性小,电性能好,耐溶剂等优点.但是,和大多数高分子材料一样,PET具有可燃性,氧指数较低等弱点.另外,随着环保要求的不断提升和人们环境意识的逐渐提高,研究和开发环保型阻燃聚酯受到了广泛的关注.而含磷阻燃剂在高温时形成具有P=O和P-O或P...     

纸基复合包装材料的应用现状及发展趋势

本文论述了纸基复合包装材料的主要性能,分析了其主要的应用领域。通过阅读文献,研究其现存的主要问题和需要改进的方面,归纳出了纸基复合包装材料的现状及其今后的发展方向。