气门镀铬层不均匀的影响因素及改进措施

影响气门镀铬层不均匀的因素有:镀铬挂具、阳极的长度和维护、防护阴极、阴阳极距离、温度、电流密度和气门来料等.介绍了气门镀铬生产和设计中应注意的问题,简要分析了各种因素对气门镀铬层质量的影响,提出了改进措施.     

不锈钢模具板化学蚀刻、抛光和电镀铬研究

研究了不锈钢模具板的化学蚀刻、化学抛光和电镀铬工艺。分析了影响蚀刻、化学抛光和电镀铬质量的因素,得到了化学蚀刻、化学抛光及电镀铬最佳工艺参数和操作规范。该工艺可以用于各种类型不锈钢的化学蚀刻、化学抛光和电镀铬处理。     

三价铬硫酸盐电镀铬的发展现状

综述了三价铬镀液电镀铬特别是三价铬硫酸盐镀液电镀铬的发展现状,对三价铬硫酸盐和氯化物镀液镀铬进行了比较.对三价铬硫酸盐镀液电镀铬的特点、工艺、镀层特性进行了评述,并列出了近几年来发展的硫酸盐电镀铬工艺,还对存在的问题和解决途径进行了探讨.     

进口气阀材料镀铬

本车间电镀的进口气阀材料从国外进口,经过精磨后再电镀硬铬,最初镀铬一次交检合格率只有50%左右,主要是铬层起皮.通过3个月的探索,获得新的镀铬工艺参数,其特点是不反电,保证了镀铬液不会因反电溶解的金属杂质的积累而报废,改革了阶梯电流的给电方法,提高了合格率.     

RL-3C稀土添加剂室温低浓度镀铬新工艺在批量生产中的运用

一、概述为了节省原材料,节省能源,减少污染。一九八七年九月初,我们电镀分厂引进了湖南稀土材料研究所研制的RL-3C稀土添加剂应用于镀铬。我们双方研究决定,不进行小槽试验,直接投入批量生产。九月十五日,把原有1200升的镀铬液经过稀释成合适工艺要求的浓度,然后加入稀土添加剂,调整好硫酸和铬酸的比例。第二天就进行生产。通过几次调整,能够每天24小时进行批量生产。为期六十天连续生产以来,我们发现,RL-3C室温低浓度镀铬工艺与常规装饰镀铬工艺进行比较有许多优点。最大的特点:室温,低浓度,工作环境大大改善,降低了能源、原材料的消耗。工作温度、电流范围宽。镀铬合格率显著提高。同时与氟化物室温低浓度镀铬工艺比较,它的特点是:沉积效率高些,复盖能力和分散能力大大提高,电流密度     

从电镀铬谈电镀生产中节能减排

通过对电镀铬生产过程的控制和对落后设备的改造,使人力资源得到合理使用、工艺参数得到有效控制、化工原材料回收利用及水资源减少消耗,达到节约能源减少排放的目的.以提高企业的效益,保护好人类赖以生存的环境.     

综合节能高效镀铬工艺

介绍了运用新型电镀铬添加剂和传统电镀铬工艺相结合,从节电、节水、节料三方面综合节能降耗,打破了只强调节电的传统思维模式和电镀工艺,解决了长期制约镀铬在综合节能降耗方面的瓶颈。     

提高钛合金零件镀铬结合力

钛合金材料镀铬工艺在航空制造业应用日渐增多,但由于镀铬层与钛合金基体结合力差,造成产品合格率较低,某制造厂家TC6、TC18钛合金镀铬产品合格率仅为50%。对钛及钛合金电镀铬存在的主要工艺难点进行研究,分步对影响因素进行实验,通过对氢化参数及乳白铬层厚度的选择,达到提高镀铬层结合力的目的。     

大件盲孔分段镀铬生产实践

为某厂生产轧机支承辊平衡中的缸筒d内径为710 mm,l=1 715 mm部位尺寸超差0.05 mm,d内径为770 mm,l =465 mm部位尺寸超差0.08 mm,属阶梯盲孔,需镀铬进行尺寸修复.按工艺规定及现有设备能力无法进行一次性镀铬,经过对工艺参数核算并采取了三项有效措施,分三段镀铬获得了成功.     

复杂零件内孔精确镀铬技术研究

本文对复杂零件内孔精确镀铬工艺进行了研究，实现了精确镀铬工装设计和制造，对槽液成分进行精确控制，以及各部位精确镀铬工艺参数优化筛选，考察了镀铬工装装挂过程的相关影响因素。实验结果表明，精确镀铬工艺避免了电镀后磨削工序对铬层和基体的各种不良影响，提高生产效率和产品质量。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

分解炉扩径的技术改造

我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

粉煤灰中烧失量检测的不确定度分析

以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。     

生物油的成分分析及物性测定

以添加FeCl2的ZnCl2-KCl混合熔盐裂解纤维素和秸秆,制得生物油。采用傅立叶变换红外光谱法和气相色谱-质谱法分析生物油的成分。结果表明,生物油中成分复杂,含有氧元素、多种有机化合物,主要包括酮类、醛类、酚类及羧酸类等。测定了20～80℃生物油的密度和粘度,发现生物油的密度与温度呈较好线性关系,而生物油的粘度均大于水的粘度,且不同熔盐体系对秸秆生物油的粘度无较大影响。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003