According to the test results of shrinkage and porosity defects, the shrinkage and porosity defects are mainly concentrated on the test blocks with thickness of 400mm and 150mm. Therefore, the change trend analysis is mainly based on the two wall thickness test blocks. The C content was used as...
After shot peening and grinding, ut test was carried out on the surface of the test block after sanding, and the volume and distribution of shrinkage and porosity of each test block were recorded. In order to fully ensure the reliability of the experimental results, the test block was...
By analyzing and mastering the proportional solidification technology of nodular cast iron into the cylinder, the cooling rate is changed by cold iron quenching, the temperature difference of cross-section is balanced from the leading position by the ladder gating system, and the liquid shrinkage is supplemented by riser feeding....
Shrinkage cavity and shrinkage porosity are common internal casting defects in heavy position of ductile iron castings. The shrinkage cavity and porosity of the intake cylinder casting are mainly distributed in the cross section of the upper 400mm stator blade flange and the wall thickness intersection area with complex...
In this experiment, the method of controlling variables is adopted. The mold temperature is set as 230 ° C, 140 ° C and 50 ° C respectively under the condition of other parameters unchanged. Through the measurement of actual mold temperature, the temperature at the bottom of the moving...
Shrinkage porosity defect is the key research object of this project. The observation method for this defect is fluorescence penetration method. Its principle is to irradiate the sample surface treated by fluorescent agent, and the penetrant entering into the hole area of the sample surface through penetration will show...
In this test, the control variable method is adopted, and the material handle thickness is set as 16mm, 31mm, 42mm and 68mm respectively under the condition that other parameters remain unchanged. According to the sample preparation and detection method mentioned above, the semi-solid die-casting samples were sawed, polished, fluorescence...
In this test, the method of variable control was adopted. Under the condition of other parameters unchanged, the boosting pressure was set to 200bar, 500bar, 800bar and loobar respectively for die casting. According to the sample preparation and detection methods, the semi-solid die casting samples were analyzed by sawing,...
Inoculation treatment: inoculation treatment of nodular cast iron can improve the roundness of graphite ball, improve the spheroidization rate, and assist the spheroidal growth of graphite. Inoculation is an important means to increase the number of graphite balls, and the number of graphite spheres has an important effect on...
The causes of shrinkage cavity and porosity of nodular cast iron are complex. The main factors affecting primary shrinkage, volume expansion and secondary shrinkage are metallurgical quality and cooling rate of molten iron, as well as the effect of spheroidizing and inoculation treatment. The metallurgical quality of nodular cast...