Cast iron electrode instructions
Cast iron is a material with poor weldability due to its high carbon content, uneven organization and low plasticity. In the welding process, white mouth, cracks and pores are easily generated. Therefore, the cast iron weld repair has high requirements on the welder's technical proficiency. The cast iron weld repair can be divided into two types: preheating and cold welding.
In order to ensure the welding effect, the following welding measures are recommended for reference and selection of castings and defects for different materials.
EZC type gray cast iron electrode
EZC type steel core strong graphitized coating cast iron welding rod, can be used for both AC and DC. The appropriate amount of graphitized elements are added to the steel core cast iron electrode. The weld can be turned into gray cast iron when it is slowly cooled. The cooling speed is fast, and the white mouth is produced and it is not easy to process. The cooling rate has a great influence on the machinability and the weld structure. Therefore, the operation process is different from the general cold welding electrode. The welding rod requires continuous welding and heat preservation after welding to make the weld be slow.
The microstructure, properties and color of the gray cast iron weld are basically similar to the base metal, but due to the poor plasticity, the welding stress cannot be relaxed and the thermal stress crack resistance is poor. The defects of small thin-walled parts with less rigidity can be pre-heated, but generally should be preheated to about 400 °C for re-welding, and then slowly cooled after welding, so as to prevent cracks and white mouth.
EZNi type pure nickel cast iron welding rod
The EZNi type is a pure nickel core strong graphitized type coated iron electrode, which can be used for all-position welding. When welding, the weldment may not be preheated. It is a kind of electrode with good comprehensive performance such as crack resistance, machinability, operation process and mechanical properties in cast iron cold-welded electrode. It is widely used in the repair of cast iron thin parts and machined surfaces. weld.
EZNiFe type nickel iron cast iron electrode
The EZNiFe type is a cast iron electrode with a nickel-iron core strong graphitized coating, which can be used for all-position welding. When welding, the weldment may not be preheated, and has the characteristics of high strength, good plasticity, excellent crack resistance, and good fusion with the base metal. Can be used for repair welding of important gray cast iron and ductile iron.
EZNiCu type nickel copper cast iron electrode
The EZNiCu type is a cast iron electrode of nickel-copper alloy core with strong graphite coating. It can be used for all-position welding. The process performance and cutting performance are close to EZNi and EZNiFe type electrodes, but due to the large shrinkage rate, the tensile strength of the weld metal is low, which is not suitable for the repair of the casting with high rigidity. It can be preheated to about 300 °C at normal temperature or low temperature. It is used for repair welding of gray cast castings with low strength requirements and good plasticity requirements.