滚筒酸洗去除气门氧化皮的研究

利用扫描电镜、X射线衍射和金相显微镜等方法研究分析喷丸和滚筒酸洗去除汽车发动机气门氧化皮的效果.结果表明:气门经热加工后,同时产生氧化皮和脱碳层缺陷,喷丸和滚筒酸洗均能有效去除氧化皮和脱碳层,但喷丸去除氧化皮会造成气门表面损伤(如折叠和微裂纹等缺陷);而滚筒酸洗能快速去除氧化皮和脱碳层,不产生表面微裂纹等缺陷,废液也能...     

化学酸洗去除钢铁氧化皮清洁生产的途径

汽车制造用钢材采用化学酸洗去除氧化皮。介绍了酸洗工艺及生产过程中废水、废气、废渣等污染物产生的来源。钢铁酸洗实施清洁生产,使用替代工艺,优化工艺规范,加强工艺管理,从而控制污染。配合末端治理,回收利用废酸液。     

不锈钢常温快速酸洗工艺

为去除不锈钢表面厚氧化皮,常用的酸洗工艺使用温度高、酸洗时间长。采用两步法酸洗工艺,可以在常温下快速去除不锈钢表面厚氧化皮,具有酸洗速度快,使用温度低的优点。酸洗液不含硝酸,环境污染小处理后表面洁净、不失光、不褪色、不泛黄。     

热轧板氧化皮结构对酸洗效果的影响分析

热轧板的氧化皮结构是其酸洗效果的主要影响之一,随着相关研究的不断深入,对热轧板氧化皮结构的分析取得了一定进展,传统氧化铁皮主要分为三层结构,分别是表层的氧化铁、中间层的四氧化三铁和里层的氧化亚铁。但在热轧板卷曲过程中,氧化皮结构受卷曲温度、终轧温度、冷却速度和环境氧气含量等因素影响,在室温下主要表现为两种结构,一是外层四氧化三铁和内层氧化亚铁的复合结构,二是四氧化三铁的单层结构。采取EBSD技术和金相显微镜对其进行研究,发现复合结构比单层结构氧化皮更容易酸洗。     

再谈汽车紧固件抛丸磷化新工艺

0 前言 汽车紧固件选择磷化处理较理想.但国内某汽车紧固件生产基地,长期沿用浓盐酸除氧化皮,常温或高温磷化老工艺.它存在以下缺点:(1)酸洗存在金属"氢脆"、"过腐蚀",并产生大量废水、废气.(2)高温磷化耗能大,恶化生产环境,工艺稳定性差,磷化缺陷多;常温磷化速率慢,时间长(≥10min),膜层薄,难以适应批量生产和满足汽车紧固件的功能要求.笔者研究了抛丸、中温复合磷化新工艺(简称磷化新工艺).该新工艺在某地区得到普遍应用.     

冷轧板表面氧化膜对镀锡板性能的影响

采用X射线光电子能谱仪(XPS)分析了冷轧板表面氧化膜的成分.再结合扫描电镜分析和电化学测试,探究了冷轧板表面氧化膜对镀锡板表面性能的影响.结果表明,冷轧板表面Mn质量分数的升高会阻碍锡层的生长,并降低锡铁合金层的致密性.通过酸洗可有效去除冷轧板表面的氧化膜,提升镀锡板表面锡铁合金层的致密性和耐蚀性.     

铍青铜材料热处理后去除氧化膜

一、概述: 铍青铜材料经热处理后(320—380℃),在表面生成一层很厚而且致密的氧化膜,给电镀的前处理带来很大的困难。按铜及铜合金酸洗通用工艺达不到质量要求。第一,氧化膜去除不干净;第二,过腐蚀严重,零件表面麻而不亮,外观不合格;第三:可焊性不好。对于酸洗后焊接的零件,由于氧化膜未除干净,故影响可焊性。为保证产品质量,经多次试验,找到了较好的酸洗工艺,酸洗后的零件光亮,无过腐蚀现象,完全符合设计要求。二、试验情况: 铜及铜合金在常温下其表面能和空气中的氧生成氧化物,经热处理在320℃—780℃的高温下,更容易氧化,生成氧化铜、氧化亚铜及氧化铍等厚而坚固的氧化膜。     

金属酸洗腐蚀促进剂的研究

经过国内外文献查阅对比,寻找有效的酸洗腐蚀加速度剂,经过20多种配方的试验对比,筛选出较好的,并可适用于高浓度盐酸,高温下快速酸洗氧化皮的酸洗腐蚀加速剂ZK-22。     

用H_2O_2—H_2SO_4混合液酸洗或化学抛光铜及铜合金

黄铜工件酸洗的目的是为了去掉在退火及其它过程中产生的氧化皮。这种氧化皮不去掉,下一步冲压成型时,会夹入工件表面中,破坏工件外观,甚至会影响后一步的(火千)焊质量。有时也会降低工件强度。同时由于氧化皮较硬,将会缩短成型模具的寿命。铜在热处理时,将形成两层氧化支。外层通常是氧化铜,呈黑色;内层通常是氧化亚铜,呈粉红色,是低温氧化的产物。把退火的铜工件,放入稀硫酸中酸洗之后,铜工件表面     

酸性缓蚀剂“协合作用”机理研究

一、前言酸洗过程广泛地应用于各种工业生产,它是清洗传热设备水垢和精整金属除去氧化皮的有效措施;在酸洗操作过程中为保护金属设备不受酸溶液的腐蚀,必须添加高效缓     

含Fe~(3+)的酸液对钢铁的腐蚀作用及其抑制

钢铁制品的酸浸去除轧制铁鳞以及换热设备酸洗除锈除垢时有Fe~(3+)产生.通过恒电位法和失重法研究了含Fe~(3+)的酸液对钢铁的腐蚀作用及其抑制,结果表明:Fe~(3+)的存在会促进钢铁的腐蚀,一定结构的硫脲衍生物和阴离子表面活性剂之间存在协同效应,能有效地抑制氢离子放电的阴极过程和Fe~(3+)还原的阴极过程,从而抑制金属的腐蚀.     

复合盐酸酸洗液在钢丝热镀锌生产中的应用

常温盐酸酸洗能耗小,对钢丝基体腐蚀性小,酸雾少,但去除铁锈和氧化皮速度较慢。盐酸酸洗液浓度较高时,酸雾逸出多,给生产环境造成了污染;同时对钢丝基体造成过腐蚀,易形成钢丝氢脆现象。在试验的基础上,优选出一种常温复合盐酸除锈酸洗液配方及浓度控制范围。生产使用结果表明,添加TX-10、SLS活性剂,含羧酸有机添加剂和磷酸都有利于提高酸洗速度,同时起到了抑制酸雾的逸出及其对钢丝的过腐蚀作用。     

KINETICS AND MECHANISM OF THE OXYPRECIPITATION OF WASTE HYDROCHLORIC PICKLING LIQUORS

The aim of the research project presented in this paper is to devise a process to treat waste liquors from the pickling of iron or steel with hydrochloric acid in rolling mills, recovering the high iron content in the form of oxides or oxyhydroxides which can later be used in other industrial processes. In addition to reducing water pollution, such a process attaches a new value to this ferrous waste.

Chlorinated liquors are oxyprecipitated, leading to the formation of different combinations of iron oxides and oxyhydroxides, with the total removal of Fe⁺² and the production of ammonium chloride solutions easily broken down into hydrochloric acid and ammonia. The precipitates have different industrial outlets, making the oxyprecipitation process an attractive solution for the treatment of waste pickling liquors.     

TREATMENT OF WASTE PICKLING LIQUORS: PROCESS SYNTHESIS AND ECONOMIC ANALYSIS

An economic analysis was carried out for three different recycle/recovery options for waste pickling liquors from hydrochloric acid pickling baths in an existing small-mid scale plant presently neutralizing and discarding waste pickling liquors. The analysis was based on process synthesis and design, which were completed by using real plant data along with some experimental work. Three basic schemes were studied: the addition of metallic iron to convert unused hydrochloric acid to ferrous chloride recovery by evaporation and recycling of a large proportion of the unused acid, and removal of ferrous chloride by crystallization to enable the recycling of the unused acid. All three schemes were evaluated at the same concentration of ferrous chloride by-product, which can be directly sold or converted later to ferric chloride, which has a higher market value. Extrapolation of existing solubility data was verified experimentally, cost estimation was done for purchased equipment and utility requirement, and feasibility analyses of the process schemes were completed. Depending on the market demand for the by-product and the criteria chosen, metallic iron addition or evaporation found to be recommendable, while the relatively more expensive crystallization process was also found to bring improvement over the no-treatment alternative.     

TREATMENT OF WASTE PICKLING LIQUORS: PROCESS SYNTHESIS AND ECONOMIC ANALYSIS

An economic analysis was carried out for three different recycle/recovery options for waste pickling liquors from hydrochloric acid pickling baths in an existing small-mid scale plant presently neutralizing and discarding waste pickling liquors. The analysis was based on process synthesis and design, which were completed by using real plant data along with some experimental work. Three basic schemes were studied: the addition of metallic iron to convert unused hydrochloric acid to ferrous chloride recovery by evaporation and recycling of a large proportion of the unused acid, and removal of ferrous chloride by crystallization to enable the recycling of the unused acid. All three schemes were evaluated at the same concentration of ferrous chloride by-product, which can be directly sold or converted later to ferric chloride, which has a higher market value. Extrapolation of existing solubility data was verified experimentally, cost estimation was done for purchased equipment and utility requirement, and feasibility analyses of the process schemes were completed. Depending on the market demand for the by-product and the criteria chosen, metallic iron addition or evaporation found to be recommendable, while the relatively more expensive crystallization process was also found to bring improvement over the no-treatment alternative.     

RELATION OF ENAMELING IRON PREPARATION AND ACCESSORY CONDITIONS TO COPPERHEAD-TYPE DEFECTS*

The tendency of blue ground-coat enamels to copperhead is shown to be related to residual iron salts formed on the surfaces of enameling iron sheets in sulfuric acid pickling. Ferrous sulfate generated in the pickling oxidizes and hydrolyzes readily into compounds which are not soluble in cyanide neutralizer. These effects may be retarded by keeping the solutions between the sulfuric acid and the neutralizer slightly acid and by minimizing the time in these solutions and the exposure to air in transferring between them. The determination of these conditions and the establishment of satisfactory procedures in the production process are described. Some accessory conditions which affect copperheading are also included.     

阀门硬化处理工艺对蒽醌法生产双氧水的影响

目前国内阀门硬化通常采用渗氮处理,渗氮工艺具有增强阀门使用寿命,提高阀门轴套耐磨性等优点。但采用渗氮工艺处理之后,继续进行酸洗钝化处理后的阀门在蒽醌法生产双氧水工艺中的应用研究较少。为了增加这一方向的研究,论文介绍了对阀杆和轴套表面进行渗氮处理的几种方法,如离子渗氮、射频渗氮、微波渗氮、离子注入和离子湮没注入的方法增加阀杆和轴套的使用寿命和耐磨性。通过对奥氏体不锈钢三偏心异径蝶阀阀杆轴套进行渗氮处理后整体酸洗,酸洗后拆检并采用双氧水进行浸泡,对不同浸泡时间的双氧水进行浓度、稳定度和铁离子的测定,根据实验结果得出渗氮工艺处理过的阀门经过酸洗后,表面会含有大量铁离子,这些铁离子的存在会导致双氧水分解,降低双氧水的浓度和稳定度,因此不适合在蒽醌法生产双氧水中应用。而仅进行酸洗钝化处理的阀门,对于双氧水影响较小,在蒽醌法生产双氧水中应用较为合适。     

SOME FACTORS INFLUENCING THE RATE OF PICKLING OF SHEET IRON1

Experiments with regard to various factors entering into pickling of sheet iron show that: (1) a freshly made sulphuric acid pickling bath pickles faster than a bath in which there is any concentration of ferrous sulphate and that (2) there is no evident advantage in adding a portion of old pickling solution to a new pickling solution “to get it to work right,” although prictical experience indicates otherwise; (3) increased ferrous chloride concentration in a muriatic acid pickling bath increases the rate of pickling; (4) ferric sulphate in a sulphuric acid bath will accelerate the rate of pickling, but will soon change to ferrous sulphate and then retard the rate; (5) decrease in acidity from usual strength decreases rate of pickling; (6) increase of temperature of bath accelerates rate of pickling; (7) iron annealed just previous to pickling loses 250–4000 more in pickling than unannealed iron; (8) use of monel metal basket accelerates the rate of pickling due to electrochemical reactions; and (9) use of muriatic acid or sodium chloride in mixtures with sulphuric acid retards the rate of pickling.     

多功能酸洗缓蚀剂缓蚀效果的研究

对威海翔宇环保科技股份有限公司研发的多功能酸洗缓蚀剂进行了盐酸酸洗、H_2SO_4酸洗、硝酸酸洗缓蚀实验,实验结果表明,多功能酸洗缓蚀剂在盐酸酸洗、H2SO4酸洗、硝酸酸洗过程中对碳钢、16mn钢都有很好的缓蚀效果,加药浓度不同,缓蚀效果不同。多功能酸洗缓蚀剂的加药浓度一般在3‰~5‰,10%的盐酸酸洗的缓蚀率可达到98.8%、10%的H_2SO_4酸洗的缓蚀率可达到99.8%、10%的硝酸酸洗的缓蚀率可达到77%以上。