The chemical composition of the nodularizer should be stable, otherwise it will seriously affect the production quality of nodular cast iron. Of course, if you are a knowledgeable person, you definitely know. The type and stability of the nodulizer produced by the nodulizer manufacturer is very important for the nodular cast iron manufacturer.
The spheroidizing element in the spheroidizing agent must be active. If it is oxidized or formed by sulfur, the spheroidizing ability is lost. Pay particular attention to the fluctuation values of Mg and RE. The main content of the nodulizer manufacturer's assessment of the nodularizing agent is the degree of deviation between the actual content of Mg and RE in the nodularizing medium and the nominal content. Generally, the blocking agent is good, and the deviation is within ± 0.2% ~ ± 0.3%. Therefore, the production of spherical substances should avoid the oxidation or sulfation of spherical elements. The higher the degree of oxidation and vulcanization, the less effective the nodulizer is. Therefore, special attention should be paid to the MgO content in the production of nodulizers.
According to Chinese standards in 1993, the sintering agent was less than 1%, but according to the test results, the sintering agent will be produced by a number of high-quality nodulizer manufacturers. The effective magnesium content can be controlled below 0.50%, which is conducive to the stability of the sintering quality. If the MgO content changes with the change of MgO, it is not appropriate to control all nodularizers with a MgO content of 1.0%. The control index is changed to MgO% / Mg % ≤0.1 + 0.02.
The supplier of nodulizing agent can directly recognize the quality of nodulizing agent by observing the breaking of nodulizing agent. The high-quality nodulizing agent is grayish blue and slightly yellow, the fractured structure is dense, and the fracture surface is metallic luster. Poor nodulizing agent has a low section density with gas shrinkage, slag inclusions and other foreign matter. The section is gray. The fracture of the alloy block should be dense without large shrinkage, porosity and slag inclusion, otherwise the density of the alloy will decrease and the alloy will float to the liquid before melting. surface.