Common welding method of N80 steel parts
Because of some advantages of N80 hollow pipe, holds the very great proportion in the automobile manufacturing materials. Cast iron parts are the basis of high precision parts, expensive, such as gas cylinder block, cylinder head, the transmission housing. Cast iron parts in the process of manufacture and use, often cracks, holes, such as damage. According to statistics, the car used in normal circumstances, reaching the wear limit of such parts, the dimensional change of only 0.08% ~ 0.40%, the mass loss only 0.1% ~ 1.8%, the scrap parts, is undoubtedly a very wasteful. Therefore, studying and using advanced experience in the repair, the reasonable repair is very necessary. Welding is a very effective method to repair parts of cast iron.
由于对N80空心管的一些优势，占有很大的比重，在汽车制造材料。铸铁件零件的精度高，价格昂贵的基础，如气缸体，气缸盖，变速器壳体。铸铁零部件在制造和使用过程中，经常出现裂纹，孔洞，如损坏。据统计，在正常使用情况下汽车，达到零件的磨损极限，只有0.08% ~ 0.40%的尺寸变化，质量损失只有0.1% ~ 1.8%，废零件，无疑是一个非常浪费。因此，研究和利用先进的修理经验，合理的修复是非常必要的。焊接修复铸铁零件的一种非常有效的方法。
Iron carbon content high, impurities, and has low plasticity, poor weldability, sensitive to the cooling rate after welding characteristics, prone to white tissue and crack. In order to improve the welding quality of cast iron parts, may adopt the following methods.http://www.dhwfg.com
1 heat welding method
Before welding workpiece whole or partial preheated to 600 ~ 700 ℃, 400 ℃ is not lower than the welding process, welding after slow cooling to room temperature. It can effectively reduce the temperature of welded joints using heat welding method, so as to reduce stress, but also can improve the plasticity of castings, to prevent the emergence of white tissue and crack.
焊前工件整体或局部预热到600 ~ 700℃，400℃不低于焊接工艺，焊后缓慢冷却至室温。它能有效地降低焊接接头的焊接方法，使用热的温度，从而降低应力，还可以提高铸件的塑性，防止白口组织和裂纹的产生。
Welding method is commonly used in gas welding and arc welding. Gas commonly used cast iron welding rod, such as HS401 or HS402, flux of CJ201, to remove the oxide. Gas welding preheating method suitable for welding of small and medium-sized thin-wall parts. Arc welding cast iron core cast iron welding rod Z248 or steel core cast iron electrode Z208, this method is mainly used for welding thickness is large (more than 10mm) of cast iron parts.
Welding equipment heat welding method mainly heating furnace, welding torch, electric furnace (stove or furnace), welding process is as follows:
1) welding preparation and preheating: remove oil and skin oxidation around the defect, the exposed metallic matrix: groove, groove depth general welding thickness of 2 / 3, the angle of 70%26deg; 120%26deg;; the welding in the stove is heated slowly to 600 ~ 700 ℃ (not exceed in 700 ℃).
1）焊前准备、预热：去除缺陷周围的油皮肤氧化，暴露的金属基质：槽，槽深度一般焊接厚度的2／3，70% 26度角；120%；26度；在炉焊接缓慢加热到600 ~ 700℃（不超过700℃）。
2) welding: a neutral flame or weak carbonizing flame (not in welding molten iron flow to the side), the base metal penetration, and then melt into the metal electrode; found in melting pool of white point, stop into the metal electrode, adding proper amount of flux, welding rod will be sorting before continuing welding; weld is smooth, weld seam after welding should be slightly higher than the cast iron surface, and will overflow in the weld slag re melting, to be cooled to a semi molten state, wire along the casting surface will be higher part scraping.
3): should generally be cooling after welding with the furnace cooled slowly to room temperature (usually takes 48h above), can also be used stone cotton (plate) or carbon covered in ash, the weld formation of homogeneous organization, at the same time, to prevent the generation of cracks.
3）：一般应随炉冷却后焊缝缓慢冷却至室温（通常需要48小时以上），也可用石棉布（板）或碳灰覆盖，组织均匀的焊缝成形，同时，防止产生裂纹。 相关资讯 没有资料