磷肥厂和硫酸厂使用的大量铸铁管道,由于强酸腐蚀和管子本身的隐患(气孔和夹杂),每年都要淘汰一大批。以我厂硫酸车间为例,仅在一年多的时间里就更换了一百多根(φ100×1500×10和φ80×1500×10毫米)管子,价值近万元。有些铸铁管仅仅因有一两个孔洞,就扔进了废铁堆。而这些管子是可焊补的,焊补工艺介绍如下: A large number of cast iron pipelines used in phosphate fertilizer plants and sulfuric acid plants have to be eliminated every year due to the strong acid corrosion and the hidden dangers (pores and inclusions) of the pipe itself. Taking the sulfuric acid plant in our factory as an example, we have replaced over 100 pipes (φ100 × 1500 × 10 and φ80 × 1500 × 10 mm) in just over a year, worth nearly RMB10,000. Some cast iron pipes are thrown into the scrap pile just because they have one or two holes. These tubes are weldable, weld repair process described below: