發(fā)黑是金屬熱處理的一種常用手段，原理是使金屬表面產(chǎn)生一層氧化膜，以隔絕空氣，達(dá)到防銹目的。nd鋼管外觀要求不高時(shí)可以采用發(fā)黑處理，鋼制件的表面發(fā)黑處理，也有被稱之為發(fā)藍(lán)的。發(fā)藍(lán)處理是一種化學(xué)表面處理,其主要作用是在工件表面形成一層致密的氧化膜,防止工件腐蝕上銹,提高工件的耐磨性,它只是一種表面處理,不會(huì)對(duì)內(nèi)部組織產(chǎn)生任何的影響,它不是熱處理,和淬火有根本的區(qū)別。
Blackening is a common means of metal heat treatment. The principle is to produce an oxide film on the metal surface to insulate the air and achieve the purpose of rust prevention. When the appearance requirement of ND steel pipe is not high, blackening treatment can be used. The surface blackening treatment of steel parts is also called blueing. Blueing treatment is a kind of chemical surface treatment. Its main function is to form a dense oxide film on the surface of the workpiece to prevent corrosion and rust of the workpiece and to improve the wear resistance of the workpiece. It is only a surface treatment, and it will not have any effect on the internal structure. It is not heat treatment, but is fundamentally different from quenching.
nd鋼管發(fā)黑處理現(xiàn)在常用的方法有傳統(tǒng)的堿性加溫發(fā)黑和出現(xiàn)較晚的常溫發(fā)黑兩種。但常溫發(fā)黑工藝對(duì)于低碳鋼的效果不太好。 堿性發(fā)黑細(xì)分出來(lái)，又有一次發(fā)黑和兩次發(fā)黑的區(qū)別。nd鋼管發(fā)黑液的主要成分是氫氧化鈉和亞硝酸鈉。發(fā)黑時(shí)所需溫度的寬容度較大，大概在135到155℃之間都可以得到不錯(cuò)的表面，只是所需時(shí)間有些長(zhǎng)短而已。 工藝： 金屬“發(fā)藍(lán)”藥液 nd鋼管采用堿性氧化法或酸性氧化法；使金屬表面形成一層氧化膜，以防止金屬表面被腐蝕，此處理過(guò)程稱為“發(fā)藍(lán)”。 黑色金屬表面經(jīng)“發(fā)藍(lán)”處理后所形成的氧化膜，其外層主要是四氧化三鐵，內(nèi)層為氧化亞鐵。 一、堿性氧化法“發(fā)藍(lán)”藥液 1．配方： 硝酸鈉50～100克氫氧化鈉600～700克亞硝酸鈉100～200克水1000克 2．制法：按配方計(jì)量后，在攪拌條件下，依次把各料加入其中，溶解，混合均勻即可。 3．說(shuō)明： （1）金屬表面務(wù)必洗凈和干燥以后，才能進(jìn)行“發(fā)籃”處理。 （2）金屬器件進(jìn)行“發(fā)藍(lán)”處理?xiàng)l件與金屬中的含碳量有關(guān)，“發(fā)藍(lán)”藥液溫度及金屬器件在其中的處理時(shí)間可參考下表。 金屬中含碳量%工作溫度（℃）處理時(shí)間（分）開始終止>0.7135-13714310-300.5-0.7135-14015030-50<0.4142-145153-15540-60合金鋼142-145153-15560-90 （3）每隔一星期左右按期分析溶液中硝酸鈉、亞硝酸鈉和氫氧化鈉的含量，以便及時(shí)補(bǔ)充有關(guān)成分。一般使用半年后就應(yīng)更換全部溶液。 （4）金屬“發(fā)藍(lán)”處理后，最好用熱肥皂水漂洗數(shù)分鐘，再用冷水沖洗。然后,又用熱水沖洗，吹于。
There are two commonly used methods for blackening treatment of ND steel pipes: traditional alkaline heating blackening and late room temperature blackening. But the effect of blackening at room temperature on low carbon steel is not very good. The alkaline blackening is subdivided into two parts, one blackening and two blackening. The main components of blackening liquor for ND steel pipe are sodium hydroxide and sodium nitrite. The temperature tolerance required for blackening is relatively large, and a good surface can be obtained between 135 and 155 degrees Celsius, but the time required is only a little longer. Process: Metal "bluing" liquid ND steel pipe adopts alkaline oxidation method or acid oxidation method; the metal surface forms an oxide film to prevent metal surface from being corroded. This process is called "bluing". The oxide film formed on the black metal surface after "bluing" treatment is mainly composed of ferric oxide in the outer layer and ferrous oxide in the inner layer. Formula: sodium nitrate 50-100 grams of sodium hydroxide 600-700 grams of sodium nitrite 100-200 grams of water 1000 grams 2. Method: According to formula measurement, under stirring conditions, each material is added in turn, dissolved, and mixed evenly. 3. Description: (1) The metal surface must be washed and dried before the "basket" treatment can be carried out. (2) The condition of "bluing" treatment for metal devices is related to the carbon content in the metal. The temperature of "bluing" liquid and the processing time of metal devices can be referred to in the table below. The treatment time (minute) of carbon content% working temperature (minute) begins to terminate > 0.7135-13714310-300.5-0.7135-14015030-50 < 0.4142-145153-15540-60 alloy steel 142-145153-15560-90 (3) periodically analyses the contents of sodium nitrate, sodium nitrite and sodium hydroxide in the solution every other week or so in order to supplement the relevant components in time. Generally, all solutions should be replaced after half a year of use. (4) After metal "bluing" treatment, it is better to rinse it with hot soapy water for several minutes and then rinse it with cold water. Then rinse it with hot water and blow it.
二、酸性氧化法“發(fā)藍(lán)”藥液
2. Acidic oxidation method "bluing" solution
1．配方： 磷酸3～10克硝酸鈣80～100克過(guò)氧化錳10～15克水1000克
1. Formula: 3-10 g phosphate, 80-100 g calcium nitrate, 10-15 g manganese peroxide, 1000 g water
2．制法：按配方計(jì)量后，在不斷攪拌條件下，依次把磷酸、過(guò)氧化錳和硝酸鈣加入其中，溶解，混合均勻即可。
2. Method of preparation: After measuring according to the formula, phosphoric acid, manganese peroxide and calcium nitrate are added in turn under the condition of continuous stirring, dissolve and mix evenly.
3．說(shuō)明： （1）金屬器件先經(jīng)洗凈和干燥后才能進(jìn)行“發(fā)藍(lán)”處理。 （2）此法所得保護(hù)膜呈黑色，其主要成分是由磷酸鈣和鐵的氧化物所組成，其耐腐能力和機(jī)械強(qiáng)度均超過(guò)堿性氧化法所得的保護(hù)膜。
3. Description: (1) Metal devices can be "blued" only after being washed and dried. (2) The protective film obtained by this method is black, and its main component is composed of oxides of calcium phosphate and iron. Its corrosion resistance and mechanical strength are higher than those obtained by alkaline oxidation method.
4.“發(fā)藍(lán)”工作溫度為100℃，處理時(shí)間為40～45分鐘。在處理碳素鋼時(shí)，藥液中磷酸含量控制在3～5克／升；處理合金鋼或鑄鋼時(shí)，磷酸含量控制在5～10克／升。應(yīng)注意定期分析藥液磷酸的含量。 5.“發(fā)藍(lán)”處理后金屬器件的清洗方法同上。 1、清洗； 2、脫脂：工件必須完全浸入脫脂液中；脫脂液濃度ph值12-14，處理時(shí)間10-30min，每過(guò)3-5分鐘上下抖動(dòng)幾次，藥液濃度低于ph12時(shí)補(bǔ)充脫脂粉； 3、水洗； 4、酸洗：酸洗液濃度ph值2-4，處理時(shí)間5-10min； 5、水洗； 6、發(fā)黑：池液濃度ph值2.5-3.5，處理時(shí)間10-12min； 7、水洗； 8、吹干 9、上油。
4. The working temperature of "bluing" is 100 C and the treatment time is 40-45 minutes. When carbon steel is treated, the content of phosphoric acid in liquid medicine is controlled at 3-5 g/l, and when alloy steel or cast steel is treated, the content of phosphoric acid is controlled at 5-10 g/l. Pay attention to periodic analysis of the content of phosphoric acid in medicinal liquid. 5. The cleaning method of metal devices after "bluing" treatment is the same as the above. 1. Cleaning; 2. Degreasing: the workpiece must be completely immersed in degreasing solution; the concentration of degreasing solution is 12-14, the treatment time is 10-30 minutes, shaking up and down several times every 3-5 minutes, the concentration of liquid medicine is lower than pH 12, adding degreasing powder; 3, washing; 4, pickling: the concentration of acid washing solution is 2-4, the treatment time is 5-10 minutes; 5, washing; 6, blackening: the concentration of pool liquid is 2.5-3.5, the treatment time is 10-12 minutes. 7. Washing; 8. Blowing and drying; 9. Oiling.
效果：（1）發(fā)黑安全不用電，用堿性高溫發(fā)黑需100%用電。（2）提高工效：共需1-2小時(shí)。（3）發(fā)黑成本低，設(shè)備簡(jiǎn)單，操作方便；對(duì)發(fā)黑時(shí)間作了嚴(yán)格的控制。（4）工藝適應(yīng)性強(qiáng)：解決了球墨鑄鐵不能發(fā)黑的難題。一種軸承套圈倒角及擋邊的發(fā)藍(lán)防銹處理工藝。軸承套圈在熱處理后經(jīng)過(guò)除油脫脂，然后在氫氧化鈉、亞硝酸鈉、硝酸鈉和水的混合溶液中進(jìn)行變色處理，其配比為2-3∶1，其余加水；加水量以溫度在 135℃-145℃為合適；時(shí)間15-25分鐘；取出套圈用清水沖洗后進(jìn)行鈍化處理，鈍化處理用重鉻酸鉀溶液作為填充液，其濃度為12%-18%；在室溫下 1-2分鐘；經(jīng)鈍化處理并干燥后，放入105℃-120℃的機(jī)油或防銹油中 1-3分鐘，至氣泡完全消失后取出，停放10-15分鐘后檢驗(yàn)。本發(fā)明生成的氧化物薄膜性能穩(wěn)定，在常溫下可長(zhǎng)期保護(hù)套圈倒角、擋邊處不生銹，軸承的外觀質(zhì)量得到明顯改善。 A3鋼用堿性發(fā)黑好一些。實(shí)際操作中，需要注意的是工件發(fā)黑前除銹和除油的質(zhì)量，以及發(fā)黑后的鈍化浸油。發(fā)黑質(zhì)量的好壞往往因這些工序而變化。
Effect: (1) Blackening is safe and does not use electricity. It needs 100% electricity to blacken with alkaline high temperature. (2) Improve work efficiency: 1-2 hours in total. (3) The blackening cost is low, the equipment is simple and the operation is convenient, and the blackening time is strictly controlled. (4) Strong process adaptability: Solve the problem that nodular cast iron can not blacken. The invention relates to a blue rust-proof treatment process for chamfering of bearing rings and shielding edges. After heat treatment, bearing rings are degreased and degreased, and then discolored in the mixed solution of sodium hydroxide, sodium nitrite, sodium nitrate and water. The ratio is 2-3:1, and the rest is added water. The appropriate amount of water is at 135-145 C. The time is 15-25 minutes. The rings are washed with clean water and passivated with potassium dichromate solution as filling liquid. Its concentration is 12%-18%. It is 1-2 minutes at room temperature. After passivation and drying, it is put into 105-120 C oil or rust-proof oil for 1-3 minutes. After the bubble disappears completely, it is removed and tested after 10-15 minutes. The oxide film produced by the invention has stable performance, can protect the chamfer and the edge of the ring for a long time under normal temperature, and the appearance quality of the bearing is obviously improved. Alkaline blackening is better for A3 steel. In practice, attention should be paid to the quality of rust and oil removal before blackening and passivation soaking after blackening. The quality of blackening often varies with these processes.