大气环境下1180MPa级超高强钢延迟开裂寿命研究

通过对试验钢进行拉深成形模拟超高强钢实际应用时的应力、应变状态,研究了盐雾和大气环境下DP1180钢、MS1180钢和QP1180钢这3种1180 MPa级超高强汽车薄板钢拉深冲杯试样的延迟开裂寿命.试验结果表明:在盐雾条件下,DP1180钢的抗延迟开裂性能最好,QP1180钢的抗延迟开裂性能最差;但大气环境下,DP1...     

GOR-Ⅱ型催化剂的工业应用

介绍了第二代催化裂化降烯烃催化剂GOR—Ⅱ的工业试验及在工业装置上的应用情况，与第一代降烯烃催化剂GOR—DQ进行了对比。对比结果表明：GOR—Ⅱ具有良好的焦炭选择性，与GOR—DQ的降烯烃能力相当，产品分布有所改善，掺渣比有所提高，可保持汽油辛烷值不小于90。     

P元素对SCu1898紫铜焊丝焊接抗裂性的影响

为避免SCu1898紫铜焊丝在焊接中出现接头裂纹,通过自主熔炼制作SCu1898紫铜焊丝,采用化学分析、着色渗透试验、金相试验和拉伸试验研究分析了不同P含量对紫铜焊接接头抗裂性、组织和力学性能的影响。试验结果显示,加P的紫铜焊丝铸锭及其焊缝熔敷金属中均会产生Cu3P脆性相,P元素的增加可增大SCu1898紫铜焊丝的裂纹倾向,随着P含量逐步增加到0.15%,焊接接头力学性能明显降低。因此,应将紫铜焊丝中P元素的质量分数控制在0.07%以下,以减少焊接过程中热裂纹倾向。     

LOSA-1增产丙烯助剂的工业应用

文中介绍了在重油催化裂化装置应用LOSA-1增产丙烯助剂,使液化气收率提高1%,丙烯收率提高2.46%的使用过程和效果.LOSA-1增产丙烯助剂在工业装置应用后达到了增加丙烯产量、提高装置经济效益的目的.     

晶体取向和载荷模式对Ni3Al合金单晶体疲劳行为的影响

在名义Ⅰ型和Ⅰ／Ⅱ复合型载荷下研究了晶体取向和加载模式对Ｎｉ３Ａｌ合金单体疲劳开裂行为的影响。结果表明：疲劳开裂行为强烈地依赖于晶体取向和加载模式。在单晶体中，站劳裂纹总是沿着具有最大切应力的滑移须开裂。根据单晶体的实验结果，解释了用三种主要的复合型断裂准则所预测的多晶体在复合型加载下的疲劳开裂行为。     

时效和回归处理对7075铝合金力学及腐蚀性能的影响

用维氏硬度计和慢应变速率拉伸（SSRT）技术研究了7075铝合金以不同制度时效和回归处理后的强度和应力腐蚀断裂（SCC）行为。结果表明：7075铝合金的强度，硬度和SCC敏感性与时效温度和时间密切相关。对于单级时效，峰时效7075－T6铝合金的强度最大，但其SCC敏感性也最大。过时效T7351及A180能显著提高合金的耐SCC性，SSRT拉伸断裂强度却下降约20％。多级时效，回归再时效（RRA）不仅能降低7075铝合金的应力腐蚀敏感性，而且能保持较高的强度。     

催化裂化汽油光化学氧化脱硫

以水为萃取剂、空气中的O2为氧化剂、500W高压汞灯为紫外光光源,研究了催化裂化(FCC)汽油光化学氧化反应的机理和氧化产物,考察了反应条件对FCC汽油脱硫率的影响。实验结果表明,FCC汽油中的极性含硫化合物首先部分溶于水相中,然后在水相中被氧化。在空气通入量为150mL/min、水与FCC汽油的体积比为1.0的条件下,反应5h后FCC汽油脱硫率达40.6%,加入0.45g4A分子筛作为O2的吸附剂后FCC汽油脱硫率提高到70.2%。FCC汽油的光化学氧化反应为一级动力学反应,加入4A分子筛时的反应速率常数为0.217 4h-1,半衰期为3.18h。FCC汽油光化学氧化反应的主要产物为亚砜和砜,并进一步生成CO2、草酸、SO24-等。     

High-pH inclined stress corrosion cracking in Australian and Canadian gas pipeline X65 steels

High-pH stress corrosion cracking is a form of environmental degradation of gas pipeline steels. The crack path is intergranular by nature and typically perpendicular to the maximum applied (hoop) stress (i.e. perpendicular to the pipe outer surface). Some unusual instances of cracks have been observed in Canadian and Australian X65 pipes, where cracks grow away from the perpendicular for considerable distances. This paper presents a comparative study in terms of crack morphology, mechanical properties and crystallographic texture for these Australian and Canadian pipe steels. It is shown that the crack morphologies are quite similar, the main difference being the angle at which the cracks propagate into the material. This difference could be explained by the different through-wall texture and grain aspect ratio measured in the two materials. The interdependency of crack tip plasticity, crack tip electrochemistry and anisotropy in microstructural texture seems to heavily affect the resulting inclined crack path.     

热载气体直接加热石油烃裂解研究进展?I. 裂解装置和技术

概述了以气体为热载体的石油烃直接加热裂解技术及其应用;介绍了热载气体直接加热石油烃裂解的装置组成、运行条件、产物产率、技术改进及发展状况,分析了裂解反应机理和反应动力学;指出热载气体直接加热裂解具有原料适用性广、产物分布灵活、热效率较高和受结焦影响小等优点,但同时也有裂解装置结构较复杂、缺乏系统性研究数据等不足. 最后对热载气体直接加热石油烃裂解的研究进行了展望,指出以氢氧燃烧产生的过热水蒸汽作为热载气体的直接加热裂解技术,在提高换热效率、降低碳排放、扩大原料范围和耦合制取合成气等方面有很大优势,发展前景广阔.     

Hydrogen production by methane cracking using Ni-supported catalysts in a fluidized bed

Nickel, supported on porous alumina (γAl₂O₃), non-porous alumina (αAl₂O₃), and porous silica, was used to catalyze methane cracking in a fluidized bed reactor for hydrogen production. The effects of temperature, PCH₄${\text{P}}_{{\text{CH}}_4}$, and particle diameter, and their interactions, on methane conversion were studied with each catalyst. Temperature was the dominant parameter affecting the hydrogen production rate for all catalysts and particle diameter had the strongest effect on the total amount of carbon deposited. Maximum methane conversion as a function of support type followed the order Ni/SiO₂ > Ni/αAl₂O₃ > Ni/γAl₂O₃. Nonetheless, better fluidization quality was obtained with Ni/γAl₂O₃. Methane conversion was increased by increasing temperature and particle size from 108 to 275 μm due to better fluidization achieved with 275 μm particles. Increasing the flow rate and methane partial pressure (PCH₄${\text{P}}_{{\text{CH}}_4}$) caused a drop in methane conversion. Tests were also run in a fixed bed reactor, and at constant weight hourly space velocity (WHSV), higher conversion was achieved in the fixed bed, but at the same time faster deactivation occurred since a higher methane conversion led to increase in carbon filament and encapsulating carbon formation rates. A critical problem with the fixed bed was the pressure build-up inside the reactor due to carbon accumulation. Finally, a series of cracking/regeneration cycle experiments were carried out in the fluidized bed reactor. The regeneration was performed through product carbon gasification in air. Ni/αAl₂O₃ and Ni/γAl₂O₃ activity decreased significantly with the first regeneration, which is attributed to Ni sintering during exothermic regeneration/carbon oxidation. However, Ni/SiO₂ was thermally stable over at least three cracking/regeneration cycles, but mechanical attrition was observed.