18MND5的焊接性能探讨

通过碳当量、冷裂纹敏感系数、热裂纹敏感系数和再热裂纹系数对18MND5进行了焊接性分析,采用埋弧焊和焊条电弧焊对18MND5进行焊接后,对焊接接头进行无损检测和力学性能试验,结果均满足标准和项目要求;并分析了焊接接头的显微组织,得到了理想的组织。试验结果表明,选用合理的措施和合适的焊接参数,采用埋弧焊和焊条电弧焊均能获得优异的焊接接头,并成功应用于产品焊接。     

焊接工艺评定试验与焊接性试验的区别与联系--压力容器制造焊接质量控制(二)

本文指出焊接工艺评定是压力容器制造焊接质量控制的重要控制环节,焊接工艺评定应以可靠的焊接性为依据,比较了焊接工艺评定试验与焊接性试验的目的、方法、作用的区别,也指出了焊接工艺评定试验与焊接性试验的联系。     

SA-336 F22 Cl.3钢焊接热处理工艺研究及应用

对SA-336 F22 Cl.3钢的焊接热处理工艺展开分析,通过钢材的焊接工艺评定试验,取得了质量可靠的焊接接头,掌握了SA-336 F22 Cl.3钢的焊接要点。最终确定了合理的焊接及热处理工艺参数,并在产品制造中应用,获得了满意的使用效果。     

09MnNiDR钢焊接接头的组织与性能

按照NB/T 47014-2011标准,对09Mn Ni DR钢焊接接头进行了理化检测,分析了焊接接头的显微组织和力学性能。结果表明,该钢焊接接头金相组织为铁素体+珠光体,焊接接头强度、低温冲击韧性满足设计文件及相关标准要求。     

20MnMoNi55钢的焊接性能

简要介绍了甲醇合成塔设备中20MnMoNi55钢焊接,通过选用焊接材料及合理的工艺参数,来实现20MnMoNi55钢焊接技术。     

压力容器筒体的焊接工艺

实施筒体的焊接工艺前,必须验证焊接接头的使用性能,从而证明压力容器筒体焊接工艺的重要性。     

哈氏合金的焊接

介绍了哈氏合金的可焊性试验 ,并给出了哈氏合金容器纵缝的焊接工艺。     

压力容器焊接工艺评定计算机管理软件的开发及应用

本文介绍了“压力容器焊接工艺评定计算机管理软件”的主要功能及特点。 该软件适用于钢制压力容器焊接工艺评定的各项管理工作。经实际使用证明,该软件对于压力容器制造企业非常实用,显著的提高了压力容器制造中焊接工艺评定的工作效率、经济效益,以及管理水平和质量。     

Design and optimization of oxidation resistant coating for C/C aircraft brake materials

A SiCN/borosilicate glass anti-oxidation coating with double-layer structure was designed for C/C aircraft brake materials. The SiCN layer was introduced as transition layer to improve the wettability between borosilicate glass and C/C composites, and the microstructure results indicated that the coating with SiCN inner layer was dense and uniform. The oxidation resistance evaluation of the coated samples was conducted at 800 °C in air for 10 h. The weight loss of SiCN/borosilicate glass coated samples valued ~ 5.66% indicated that the oxidation resistant property of the simple SiCN/borosilicate glass coating was not good, which was mainly due to the relative large viscosity of borosilicate glass at 800 °C. B₄C was introduced to add into the outer glass coating to improve the self-healing ability of the coating. After oxidized at 800 °C in air for 10 h, the weight loss of the SiCN/borosilicate glass-B₄C coated samples was ~ 2.48%. B₄C could consume the oxygen diffused into the coating and the reacted product B₂O₃ with a better fluidity at 800 °C could effectively heal cracks and pores in the coating to improve the oxidation resistance property. The reaction of B₄C oxidized to B₂O₃ was accompanied with ~ 1.5 times volume expansion, which was also beneficial for the healing of defects.     

C.I.活性蓝19及其对位异构体性能的研究二、染色性能的研究

研究了C.I.活性蓝19及其对位异构体的上色性能及固色性能,并计算出它们的直接性S、竭染率E、固色率F、反应性R值,通过比较,分析了其结构与染色性能的关系。结果发现:C.I.活性蓝19反应活性较高,固色性能较好;而C.I.活性蓝19对位异构体对纤维的亲和力较大,上色性能较好。两只染料的最终固色率接近。     

WC含量对Ti(C,N)基金属陶瓷组织和性能的影响研究

用传统的粉末冶金方法制备了不同WC含量的超细Ti(C,N)基金属陶瓷试样,运用SEM,EDX等手段对材料的显微组织进行了表征分析,并用这些显微组织的特征和差异解释了材料宏观力学性能的特点.结果表明,金属陶瓷的组织为典型的两相结构特征,其中陶瓷相的芯、壳结构(core/timstructure)与溶解析出机制有关.少量WC的加入能提高材料的力学性能.断口SEM分析表明:断裂机理为典型的混合型断裂(穿晶断裂和沿晶断裂),金属相存在着明显撕裂的痕迹.     

电解法处理C.I. Reactive Red 241、C.I. Disperse Blue 56模拟染料废水的研究

以C.I.Reactive Red 241、C.I.Disperse Blue 56模拟染料废水为对象,研究了电解法处理该类染料废水的优化条件。考察了起始电压、电解时间、溶液初始p H对处理效果的影响。结果表明,在p H=7,U=14V、I=3.2A、t=30min的条件下,C.I.Reactive Red241模拟染料废水的脱色率可达到86%以上;在p H=7,U=14V、I=3.2A、t=25min的条件下,C.I.Disperse Blue 56模拟染料废水的脱色率可达到79以上%。     

A.C. Conductivity and Dielectric Properties of Polycarbonate Sheet

ABSTRACT

The a.c. conductivity σ_a.c(ω), the dielectric constant ?′ and dielectric loss ?″ of polycarbonate sheet have been studied in the frequency range 1.5 × 10²–5 × 10⁶ Hz and temperature range 294–473 K. A.c. conductivity σ_a.c(ω) results show that it depends strongly on the frequency and slightly on the temperature, with activation energy between 0.0003 and 0.085 e.V. The a.c. conductivity σ_a.c(ω) as a function of frequency is well described by a power law Aω^S where S is the frequency exponent. The obtained values of S < 1 in the first region over the frequency range 1.5 × 10²–4 × 10³ Hz, the temperature dependence of both a.c. conductivity σ_a.c(ω) and the parameter S are reasonably well interpreted by the correlated barrier hopping (CBH) model. The second region, where S > 1 over the frequency range 4 × 10³–5 × 10⁶ Hz, has a strong dependence on the frequency but near independence of the temperature, suggesting that the conductivity may be interpreted by the Maxwell–Wagner (M–W) dispersion. In the first region, the optical band gap of the material, E_g, and the maximum barrier height, W_m, are calculated, suggesting that there is agreement with that proposed by the theory of hopping of charge carriers over potential barrier as suggested. Spatial inhomogeneity may affect the conduction mechanisms in polycarbonate. The experimental values of dielectric constant, ?′ and dielectric loss, ?″, show their dependence on temperature and frequency.     

C.I.颜料红146的合成和改性

讨论了主要合成条件和表面活性剂对C.I.颜料红146性能的影响。结果表明:合成C.I.颜料红146的较好工艺条件为:顺式偶合,偶合时间1小时,偶合结束pH为5.0,升温至90℃,保温30分钟,产品在80℃下干燥。添加表面活性剂后可得到色光偏蓝,着色力较高,分散性较好的C.I.颜料红146产品。     

Ti(C,N)基金属陶瓷氧化后的显微结构与力学性能

研究了Ti(C,N)基金属陶瓷的高温抗氧化性能。采用X R D、SEM分析了样品氧化后的物相组成及显微结构,并测试了试样氧化前后的抗弯强度和维氏硬度。实验结果表明:Ti(C,N)基金属陶瓷在800℃时氧化不明显,但抗弯强度开始下降;样品在900℃时开始剧烈氧化,材料的抗弯强度呈现明显的下降趋势,试样氧化前后的硬度变化较小。随着氧化温度的升高,氧化层厚度明显增加,Ti(C,N)被氧化变成TiO 2。     

野生植物值叶薯蓣营养成分的研究及应用

对野生植物c进行了分析,结果表明,值叶薯蓣中含有多种营养成分,丰富的矿质元素和维生素及其-β胡萝卜素。值叶薯蓣中至少含有17种氨基酸。旨在为开发利用植物资源提供科学依据。