How to identify the quality of solder iron pipes

Ductile tube is short for ductile iron pipes, ductile iron pipes is the main raw material is pig iron, centrifugal ductile iron pipes is pig iron to add a certain proportion of carbon, silicon, manganese, sulfur, phosphorus and magnesium spheroidizing agents and then internal and external anticorrosion. Graphite in nodular cast iron exists in spherical form, the size of the general graphite is 6-7 grade, the quality requirements of the cast pipe spheroidization grade control for 1-3 grade (spheroidization rate ≥80%), so the mechanical properties of the material itself has been better improved, with the nature of iron, steel performance, excellent anti-corrosion performance, good ductility, easy installation. Mainly used in industrial and mining enterprises for water supply, gas, oil and so on. But how to identify the quality of ductile iron pipes, check whether ductile iron pipes qualified?
1. The appearance of inferior drainpipes is often pockmarked. Pockmarked surface is an irregular and uneven defect on the surface of the drain pipe caused by severe rolling groove wear. Because of the poor quality pipe manufacturers to pursue profit, there are often excessive groove rolling.
2. The surface of inferior drainpipes is prone to scarring.
3. Cracks are easy to occur on the surface of inferior materials, because its billet is adobe, and the adobe has many pores. In the process of cooling, due to the action of thermal stress, the adobe produces cracks, and there are cracks after rolling.
4. Inferior drainage pipes are easy to scratch, the reason is that inferior material manufacturers simple equipment, easy to produce burrs, scratch the surface of the drainage pipe. Deep scratching reduces the strength of the ball drain.
5. Inferior drainpipes have no metallic luster and are light red or similar to pig iron.
6. Poor quality ductile iron pipes are easy to fold. Folding is a variety of lines formed on the surface of iron pipes, and this defect generally runs through the longitudinal aspect of the entire product.