Wide range of applications
With its excellent physical properties and significant economic advantages, ductile iron is gradually becoming the material of choice in many industrial fields, widely replacing traditional materials such as forged steel, stamped steel, weldments, malleable cast iron, gray cast iron and cast steel. In the United States, this trend is particularly obvious. Ductile iron has occupied an important share of the market and has successfully replaced different proportions of the above-mentioned materials, demonstrating its unparalleled application potential and market competitiveness.
| Application fields | Typical castings in Ductile Iron | Performance characteristics | Brand |
| Water, gas and oil pipelines | Centrifugally cast pipes and fittings, with a diameter less than or equal to 2600 mm | Pressure resistance, corrosion resistance, earthquake resistance and soil resistance | |
| Cars, tractors | Crankshaft, camshaft, connecting rod, gear, drive axle housing, balance shaft bracket, differential housing, etc. | Wear-resistant, fatigue-resistant, high strength and toughness, able to withstand impact loads at -40°C | QT900-2 QT800-2 QT700-2 QT600-3 QT400-8 QT450-10 |
| Ships, locomotives, diesel engines | Crankshaft, connecting rod, camshaft, gear, cylinder liner | Wear-resistant, fatigue-resistant, high strength | QT900-2 QT800-2 QT700-2 QT600-3 |
| Agricultural machinery | Machine-driven plow posts, machine-driven harrows, shaft covers, harvesters, blade guards, gears | High toughness, impact load resistance | QT400-15 QT450-10 QT500-7 |
| Hydraulic parts | Valve body, pump body | Oil pressure resistant and wear resistant | QT400-15 QT450-10 |
| Lifting conveyor | Gears, shafts, crane wheels | Wear-resistant, high strength | QT900-2 QT800-2 QT700-2 QT600-3 |
Production composition analysis
From the perspective of production structure, the production of ductile iron is dominated by ferrite matrix, accounting for 60% of the total output, while pearlite matrix follows closely behind and occupies a place. In addition, the mixed matrix of ferrite and pearlite also accounts for a considerable proportion. The three together account for almost 95% of all ductile iron production, highlighting the dominant position of these two matrices in the production of ductile iron.
Excellent mechanical properties analysis
The key reason why ductile iron can stand out among many materials lies in its unique mechanical properties. It does not have a yield point in the traditional sense, and the stress-strain curve shows continuous gradient characteristics above the proportional limit. This characteristic stems from the unique behavior of graphite balls under stress: when the stress exceeds the elastic limit, although the graphite balls appear to be part of the matrix, they actually no longer deform, forming gaps in the longitudinal direction, resulting in volume expansion, and this expansion cannot Compensated by lateral compression.
Performance comparison with other materials
Gray cast iron: Traditionally, only tensile strength is used as a performance indicator, and the highest grade has limited tensile strength (only 350MPa). In contrast, ductile iron shows significant advantages in both strength and plasticity.
Malleable cast iron: Although it has plasticity indicators, whether it is black-core, pearlite or white-core malleable iron, its comprehensive mechanical properties are not as good as ductile iron.
Cast steel and structural steel: Although it has excellent performance in post-fracture elongation and impact toughness, the yield strength is not as good as that of ductile iron, further highlighting the superiority of ductile iron in specific applications.
Post time: Sep-18-2024