High silicon molybdenum ductile iron material

Abstract

The invention discloses a high-silicon-molybdenum ductile iron material. The high-silicon-molybdenum ductile iron material contains: C: 2.90%-3.35%; Si: 4.40%-4.80%; Mo: 0.50%-0.75%; Cr: 0.30% to 0.50%; V: 0.20% to 0.45%; Mn: 0.10% to 0.30%; Mg: 0.04% to 0.07%; P: ≤0.07%; S: ≤0.02%; the rest is Fe. The tensile strength of the high-silicon-molybdenum ductile iron material is ≥710MPa, the yield strength is ≥500MPa, the elongation is ≥10%, and the hardness is 230-265HBW5 / 750. The high silicon molybdenum ductile iron material also contains trace amounts of Sn and Sb. The high-silicon-molybdenum ductile iron material of the present invention eliminates fragmented graphite and graphite deterioration layer, ensures the spheroidization level at different wall thicknesses, and simultaneously solves defects such as micro-shrinkage porosity.

Description

[0001] This application is a divisional application of the invention patent application with the application number 201210499812.6 and the application date is November 29, 2012, and the invention name is "high silicon molybdenum nodular iron material and its preparation method". technical field [0002] The invention relates to a ductile iron material, in particular to a high-silicon-molybdenum nodular iron material used for high-temperature-resistant parts of automobiles. Background technique [0003] High-silicon-molybdenum ductile iron is widely used in automotive high-temperature resistant parts such as exhaust pipes and turbine shells due to its high high-temperature strength, thermal fatigue resistance, excellent oxidation resistance, growth and good high-temperature creep resistance. . With the improvement of people's awareness of environmental protection and regulations, HT250 and even vermicular iron materials can no longer meet the performance requirements of engin...

AI Technical Summary

Problems solved by technology

[0004] However, the biggest problem currently existing in high-silicon-molybdenum ductile iron is that due to the high content of silicon and molybdenum, it is brittle, prone to produce fragmented graphite and graphite deterioration layers, and prone to micro-shrinkage, which leads to metallographic Organizations Difficult to Meet

However, the addition of vanadium and chromium is easy to form carbides, making it more brittle and more likely to produce fragmented graphite and microscopic shrinkage.

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