What should be done when welding ductile iron? The specific welding method is like this. I will give you a detailed introduction below.
Ductile differs from gray cast iron , it is the mechanical properties of the ball so as to improve the treatment significantly , mainly for producing high mechanical performance requirements of the casting , may also be manufactured in steel instead of carbon steel or high strength in a certain range , Castings with complex shapes. This requires that when welding, it is necessary to ensure that no welding defects are generated , but also from the perspective of strength , so that the weld has better strength and plasticity. Magnesium alloys are commonly used as spheroidizing agent for ductile iron , and magnesium is an element that hinders graphitization , which will cause white-mouth structure during welding . This is one of the main difficulties in welding ductile iron. If the cooling rate is too fast welding , the HAZ austenite into martensite , form a hardened tissue , it is more difficult after the welding process. Ductile iron because strength and plasticity is preferably itself , is generally hard to crack during welding , but it requires high welding quality than gray cast iron , relatively speaking, more difficult to weld. So how do we weld ?
Electrode arc welding
generally can be welded with EZCQ (Z238) ductile iron electrode , preheated before welding 500 ~ 700 ℃ , after welding, according to the requirements of the matrix structure , it can be normalized or annealed. Cold welding of ductile iron is mainly used for welding electrodes such as EZNiFe-1 (Z408) and EZNiFeCu (Z508) , which are mainly used for welding repair of non-machined surfaces , and the process is the same as that of gray cast iron.