Product Introduction

Measurement and calculation method of graphite nodulation rate of nodular casting

According to the metallurgical standard of ductile iron, the measurement conditions of spheroidization rate are: The sample is polished without erosion, observation and measurement The measurement field is the graphite within the diameter of 70mm, the graphite cut with the outer circle is not included in the measurement count, the observation and photo magnification is 100 times, the observation field is not measured when the diameter of the graphite ball is less than 2mm, the number of graphite balls in the field of view is not less than 20, the graphite ball diameter is less than 12mm or greater than 12mm, The magnification can be changed appropriately, and the graphite in the observed field of view is usually compared with the standard control and the grade is determined.

Method for identification of graphite in castings by optical microscopy

When the metallography of nodular and gray iron castings is observed by optical microscope, the planar morphology of graphite has a non-metallic appearance, showing the anisotropy and reflection polychromism of graphite. Under unpolarized light, the graphite appears light grayish brown, and under plane polarized light, the graphite appears light gray to black. In cast iron, the graphite phase can be recognized only after polishing and proving its optical anisotropy and reflected polychromatism.

When observing graphite in nodular casting and gray iron casting under bright field unpolarized light, the graphite is non-directional and does not produce polarization effect, the graphite phase is uniform and light gray, when inspected under bright field polarized light, the graphite has obvious polarization effect, in some directions the graphite has strong reflective ability and is obviously bright, while in other directions the color is dark, and the dark field technology can also be used to check the graphite. When observed under the condition of dark field polarized light, the graphite appears as a cross shape intersecting light and dark.

Develop the advantages of ductile casting

If the history of the development of cast iron is driven by high strength, then his further development is still so, which includes the following:

Further development of the highest strength ductile castings in the field of cast iron; 2. Further improvement of the strength of various other cast iron (gray cast iron, malleable cast iron, Confucian cast iron, etc.); 3. In the field of cast iron, the proportion of high strength cast iron, especially high strength and high toughness ductile cast iron, is large. The proportion of ductile casting and steel casting in China, as well as the proportion of ductile cast iron in cast iron are unreasonable, the widespread use of ductile cast iron, so that it accounts for 15%-25% of the total weight of cast iron, which is one of the most economical and effective ways to reduce the weight of castings and improve technical and economic benefits. Substituting ductile iron for cast steel can reduce its weight by 8%-12%, replacing gray cast iron with ductile iron, the tensile strength can be increased by 1-2 times, and the weight of the casting can be reduced by 15%-30%.

Zhongwei Precision has the following services

Detection Systems

Copper Silica Sol Investment Casting

We are the manufacturer of "SG500 Slash/7 Ductile Iron Parts", if you need more information please contact us!