提高镀锌层厚度控制精度与均匀性的方法

发布日期：2018-12-04 作者：点击：

提高镀锌层厚度控制精度与均匀性的方法
① 控制锌液成分
　　往锌液中加入适量的Al可降低Fe的含量。锌液中的Al与Fe反应生成Fe2Al5形成浮渣，消耗锌液中的Fe。实践表明，锌液中Al的质量分数在0.16～0.25%之间较为适宜，Fe的质量分数最好控制在0.01%以下。实际生产中，要求对锌液的化学成分进行取样分析，根据分析结果来添加不同Al含量的锌锭以达到控制锌液成分的目的。另有研究表明，在锌液中添加质量分数为0.01～0.1%的稀土元素能改善锌液流动性，细化镀层晶粒，减薄镀层厚度，净化锌液，减少锌瘤、锌灰的产生和锌的无效损耗，同时提高镀锌层的耐蚀性和表面光泽度。

① kòng zhì xīn yè chéng fèn

　　wǎng xīn yè zhōng jiā rù shì liàng de Alkě jiàng dī Fede hán liàng 。xīn yè zhōng de Alyǔ Fefǎn yīng shēng chéng Fe2Al5xíng chéng fú zhā ，xiāo hào xīn yè zhōng de Fe。shí jiàn biǎo míng ，xīn yè zhōng Alde zhì liàng fèn shù zài 0.16～0.25%zhī jiān jiào wéi shì yí ，Fede zhì liàng fèn shù zuì hǎo kòng zhì zài 0.01%yǐ xià 。shí jì shēng chǎn zhōng ，yào qiú duì xīn yè de huà xué chéng fèn jìn háng qǔ yàng fèn xī ，gēn jù fèn xī jié guǒ lái tiān jiā bú tóng Alhán liàng de xīn dìng yǐ dá dào kòng zhì xīn yè chéng fèn de mù de 。lìng yǒu yán jiū biǎo míng ，zài xīn yè zhōng tiān jiā zhì liàng fèn shù wéi 0.01～0.1%de xī tǔ yuán sù néng gǎi shàn xīn yè liú dòng xìng ，xì huà dù céng jīng lì ，jiǎn báo dù céng hòu dù ，jìng huà xīn yè ，jiǎn shǎo xīn liú 、xīn huī de chǎn shēng hé xīn de wú xiào sǔn hào ，tóng shí tí gāo dù xīn céng de nài shí xìng hé biǎo miàn guāng zé dù 。

②控制气刀参数
　　气刀参数的调整往往和合同锌层厚度、机组的生产速率等有关。气刀角度和气刀刀唇的开口度因为调整难度大，精度要求高，需专业人员进行调整，一般在安装前即已调好，正常生产时不再进行调整。在实际生产中主要调整气刀高度、气刀与带钢距离和气刀压力三个参数。气刀高度的调整视机组生产速率和气刀压力的大小进行调整。当生产速率高，气刀压力大时，气刀高度应调高些以防止锌液飞溅堵塞气刀刀唇；反之则调低些，以避免镀层边部增厚。在生产镀层较薄的产品时，为避免气刀压力过大造成锌液飞溅，一般首先将气刀与带钢距离调小，但应注意不能调得过小（一般不能小于8 mm），否则也容易发生气刀刀唇堵塞。生产每一组镀层厚度要求的产品，都对应有一组最佳气刀参数，可存入气刀设备的数据库系统，以便今后生产相同镀层要求的产品时调出使用。

②Controlling parameters of air knife

The adjustment of air knife parameters is often related to the thickness of zinc layer and the production rate of the unit. The angle of air knife and the opening of air knife lip need to be adjusted by professionals because of the difficulty of adjustment and the high accuracy requirement. They are usually adjusted before installation and no longer adjusted during normal production. In actual production, the height of air knife, the distance between air knife and strip steel and the pressure of air knife are mainly adjusted. The height of air knife is adjusted according to the production rate and the pressure of air knife. When the production rate is high and the pressure of air knife is high, the height of air knife should be raised to prevent zinc splash from blocking the lip of air knife; conversely, it should be lowered to avoid the edge thickening of coating. In the production of thin coated products, in order to avoid the spatter of zinc liquid caused by excessive pressure of air knife, the distance between air knife and strip steel should be reduced firstly, but attention should be paid not to adjust too small (generally not less than 8 mm), otherwise, air knife lip blockage will easily occur. For each group of products with coating thickness requirements, there is a set of optimum parameters of air knife, which can be stored in the database system of air knife equipment, so that it can be used in future production of products with the same coating requirements.

③改善带钢的板形
　　带钢的板形不好，容易发生抖动，从而导致带钢表面镀层厚薄不均。因此，要使带钢表面镀层厚度均匀一致，就必须控制好带钢的板形。锌锅段带钢板形的控制主要通过张力的控制和校正辊位置的调整来实现。带钢张力与带钢的材质与规格、机组速率相匹配，其调整范围存在局限性。实际生产中，校正辊位置的调节也是调整带钢板形时经常使用的方法。
　　图1为两种典型的带钢板形及其镀层厚度显示，这种板形通常是由锌锅段过大的张力或稳定辊位置不匹配造成的。带钢中部向机组出口方向凸出，得到的镀层"上凸下凹"（带钢面向机组入口方向一面为上表面，面向出口方向一面为下表面）；的带钢中部向机组入口方向凸出，得到的镀层则"上凹下凸"。带钢上表面中部到两边受到的气刀气流冲量逐渐增大，被吹刮掉的锌液逐渐增多，反映在镀层厚度上便是中间厚两边薄，下表面的情况则刚好相反，也是相同原理。为改善带钢板形，可以将校正辊往远离带钢的方向调整；则可将校正辊往靠近带钢的方向推入。

③gǎi shàn dài gāng de bǎn xíng

　　dài gāng de bǎn xíng bú hǎo ，róng yì fā shēng dǒu dòng ，cóng ér dǎo zhì dài gāng biǎo miàn dù céng hòu báo bú jun1 。yīn cǐ ，yào shǐ dài gāng biǎo miàn dù céng hòu dù jun1 yún yī zhì ，jiù bì xū kòng zhì hǎo dài gāng de bǎn xíng 。xīn guō duàn dài gāng bǎn xíng de kòng zhì zhǔ yào tōng guò zhāng lì de kòng zhì hé xiào zhèng gǔn wèi zhì de diào zhěng lái shí xiàn 。dài gāng zhāng lì yǔ dài gāng de cái zhì yǔ guī gé 、jī zǔ sù lǜ xiàng pǐ pèi ，qí diào zhěng fàn wéi cún zài jú xiàn xìng 。shí jì shēng chǎn zhōng ，xiào zhèng gǔn wèi zhì de diào jiē yě shì diào zhěng dài gāng bǎn xíng shí jīng cháng shǐ yòng de fāng fǎ 。

　　tú 1wéi liǎng zhǒng diǎn xíng de dài gāng bǎn xíng jí qí dù céng hòu dù xiǎn shì ，zhè zhǒng bǎn xíng tōng cháng shì yóu xīn guō duàn guò dà de zhāng lì huò wěn dìng gǔn wèi zhì bú pǐ pèi zào chéng de 。dài gāng zhōng bù xiàng jī zǔ chū kǒu fāng xiàng tū chū ，dé dào de dù céng "shàng tū xià āo "（dài gāng miàn xiàng jī zǔ rù kǒu fāng xiàng yī miàn wéi shàng biǎo miàn ，miàn xiàng chū kǒu fāng xiàng yī miàn wéi xià biǎo miàn ）；de dài gāng zhōng bù xiàng jī zǔ rù kǒu fāng xiàng tū chū ，dé dào de dù céng zé "shàng āo xià tū "。dài gāng shàng biǎo miàn zhōng bù dào liǎng biān shòu dào de qì dāo qì liú chōng liàng zhú jiàn zēng dà ，bèi chuī guā diào de xīn yè zhú jiàn zēng duō ，fǎn yìng zài dù céng hòu dù shàng biàn shì zhōng jiān hòu liǎng biān báo ，xià biǎo miàn de qíng kuàng zé gāng hǎo xiàng fǎn ，yě shì xiàng tóng yuán lǐ 。wéi gǎi shàn dài gāng bǎn xíng ，kě yǐ jiāng xiào zhèng gǔn wǎng yuǎn lí dài gāng de fāng xiàng diào zhěng ；zé kě jiāng xiào zhèng gǔn wǎng kào jìn dài gāng de fāng xiàng tuī rù 。