Cast Iron Machine Tool Bases (Large-Scale Cast Iron Equipment Foundation Components): Core Foundation for Ultra-Load-Bearing Capacity and Long-Term Stability of Heavy-Duty Equipment

Overview of the Solution

This cast iron machine tool base and large-scale cast iron equipment foundation component is specifically designed for high-end heavy-duty equipment such as heavy-duty CNC lathes, gantry machining centers, metallurgical rolling mills, wind turbine main frames, and heavy-duty testing equipment. With “high-rigidity cast iron material + large-scale precision manufacturing + anti-deformation structural design” as the core, it overcomes the four major pain points of traditional foundation components: “insufficient load-bearing capacity leading to easy cracking, poor machining accuracy of large sizes, excessive deformation during long-term use, and difficulty in ground adaptation”.

High-strength gray cast iron (HT350/HT400) and ductile iron (QT600-3/QT700-2) are carefully selected. Through the “large-scale CNC boring and milling machine + aging strengthening” process, it achieves a maximum single-piece size of 10000×5000×1800mm, a load-bearing capacity of 50-300 tons, a flatness of ≤0.01mm/1000mm, and a long-term precision attenuation rate of ≤0.08% per year.

It covers industries such as heavy machinery manufacturing, metallurgy, wind power, and aerospace. It helps to increase the machining accuracy of heavy-duty equipment by 25%, extend the service life by 3 times, and reduce the installation and commissioning cost of large-scale equipment by 30%.

Core Function System (Focusing on “Foundation Support” and “Large-Scale” Characteristics)

1. Exclusive Materials and Processes for Large-Scale Foundation Components

• Selection of High-Strength Cast Iron Materials:

◦ HT350/HT400 Gray Cast Iron: The main material for cast iron machine tool bases. It has a tensile strength of ≥350MPa (for HT350) / 400MPa (for HT400) and a hardness of 200-260HB. The optimized flake graphite distribution enhances shock absorption (the shock absorption coefficient is 4-6 times that of steel), which can absorb high-frequency vibrations generated by the operation of the spindle of heavy-duty machine tools (10000-15000rpm) and avoid machining vibration marks. It is suitable for machine tool bases with a single-piece weight of ≤80 tons and a size of ≤6000×4000mm (such as heavy-duty CNC lathe bases and gantry milling machine bases).

◦ QT600-3/QT700-2 Ductile Iron: The core material for large-scale equipment foundation components (such as rolling mill foundation bases and wind turbine main frame foundations). It has a tensile strength of ≥600MPa (for QT600-3) / 700MPa (for QT700-2) and an elongation of ≥3%. Its toughness is 3-4 times that of gray cast iron, and it can withstand 300-ton-level impact loads (such as rolling force in steel rolling and operating impact of wind power equipment) to avoid cracking of foundation components. With a hardness of 220-280HB, it has both anti-fatigue and wear-resistant properties, making it suitable for scenarios with strong impact and high load.

◦ Process Guarantee for Large-Scale Foundation Components: The “resin sand negative pressure molding + lost foam casting” composite process (for complex large-scale parts) is adopted to reduce air holes and shrinkage defects in large-scale castings (defect rate ≤0.3%). After 90-120 days of natural aging (50% longer than conventional castings) + 3 times of artificial aging treatment (holding at 550-600℃ for 8 hours), more than 99.5% of internal stress is eliminated, avoiding long-term deformation of large-scale foundation components due to stress concentration (deformation ≤0.1mm/m in 10 years), which is far better than that of welded structure foundation components (deformation ≥0.5mm/m in 5 years).

• Enhancement of Stability Under All Working Conditions:

To address the problem of “thermal deformation sensitivity” of large-scale foundation components, through “gradient wall thickness design” (the wall thickness of key load-bearing parts is 80-150mm, and that of non-load-bearing parts is 50-80mm) and “integrated heat dissipation ribs”, the thermal deformation of a 10m-long foundation component is controlled within ≤0.005mm/m (with an ambient temperature fluctuation of ±10℃). The surface adopts a three-layer protection of “sandblasting derusting + epoxy primer + wear-resistant topcoat”, which can pass a salt spray test of ≥720 hours. It is suitable for the high-temperature (≤150℃) and high-dust environment of metallurgical workshops and the cutting fluid erosion environment of machine tool workshops, avoiding the impact of foundation component rust on stability.

2. Ultra-Load-Bearing and Anti-Deformation Structural Design

• Box-Type + Honeycomb Rib Reinforced Structure:

◦ Cast Iron Machine Tool Bases: The “box-type main structure + cross-shaped reinforcing ribs” design is adopted (rib spacing 300-500mm). For example, a 6000×3000×800mm heavy-duty CNC lathe base has a 60% increase in bending stiffness. When bearing the weight of a 50-ton workpiece + spindle box for a long time, the deformation is ≤0.003mm/m, avoiding the parallelism deviation between the spindle and the guideway during machine tool machining (deviation ≤0.002mm/1000mm).

◦ Large-Scale Equipment Foundation Components: For ultra-load scenarios such as rolling mills and wind power equipment, the “box-type structure + honeycomb dense ribs” design is adopted (rib spacing 200-300mm). For example, an 8000×4000×1500mm rolling mill foundation base has a compressive strength of ≥200MPa. When bearing the entire 200-ton rolling mill, the settlement of the foundation component is ≤0.005mm, ensuring the stable reference of the equipment during the rolling process.

• Precision Machining of Datum Planes and Mounting Holes:

The “large-scale CNC boring and milling machine (stroke 12000×5000×2000mm) + large-scale surface grinding machine” composite machining is adopted to achieve:

◦ Mounting Surface of Machine Tool Bases: The flatness is ≤0.01mm/1000mm, the straightness of the guideway mounting surface is ≤0.008mm/1000mm, and the positional tolerance of the hole system (φ50-φ200mm positioning holes) is ±0.015mm. It is suitable for the precise installation of machine tool guideways and spindle boxes, reducing the reference adjustment time during assembly.

◦ Interface of Large-Scale Equipment Foundation Components: The flatness of the equipment mounting surface is ≤0.015mm/1000mm, the positional tolerance of the anchor bolt holes (φ80-φ150mm) is ±0.02mm, and equipment leveling holes (spacing 1000-2000mm) are reserved to facilitate on-site precise leveling and adapt to the fixed installation of large-scale equipment such as rolling mills and wind turbine main frames.

• Splicing Technology for Ultra-Large-Scale Parts:

For ultra-large-scale foundation components with a length of ≥10m (such as the foundation of a 12m-long large coordinate measuring machine), the “block casting + on-site splicing” technology is adopted: the splicing surfaces are processed with spigots (tolerance H7/h6) to ensure that the vertical/horizontal misalignment is ≤0.005mm; M40-M60 high-strength splicing bolts (tensile strength ≥Grade 12.9) are matched, and the overall flatness after splicing is ≤0.015mm/1000mm. The overall load-bearing capacity does not decrease (the load-bearing strength at the splicing joint is ≥95% of the main body), solving the pain point that traditional large-scale foundation components “cannot be transported due to integral casting”.

3. Ground Adaptation and Multi-Scenario Application

• Multi-Method Ground Installation Adaptation:

◦ Embedded Installation: Large-scale foundation components (such as rolling mill foundation bases) are embedded in the ground concrete (concrete strength ≥C30) and connected to the foundation components through embedded steel bars to enhance overall stability, which is suitable for heavy-duty equipment that is fixed for a long time.

◦ Ground Fixed Installation: Cast iron machine tool bases are fixed on the ground through expansion bolts (M30-M50), and heavy-duty adjustment pad irons (load-bearing ≤50 tons/set, adjustment range 0-20mm, horizontal accuracy ±0.001mm/m) are matched at the bottom, facilitating later precision adjustment and adapting to the regular calibration needs of machine tool equipment.

◦ Shock Absorption Installation: For vibration-sensitive equipment (such as the foundation of precision testing machines), air spring shock absorption modules (shock absorption efficiency ≥90%) are installed at the bottom of the foundation components to isolate ground vibrations (such as the operation of other equipment in the workshop) and ensure the operating accuracy of the equipment (detection repeatability error ≤0.003mm).

• Adaptation to Multiple Types of Heavy-Duty Equipment:

◦ Heavy-Duty CNC Lathe Bases: Made of HT400 material, with a size of 6000×3000×800mm, a load-bearing capacity of ≤80 tons, and a straightness of the guideway mounting surface of ≤0.008mm/1000mm. It is suitable for processing φ2000mm wind power main shafts and ship crankshafts.

◦ Rolling Mill Foundation Bases: Made of QT600-3 material, with a size of 8000×4000×1500mm, a load-bearing capacity of ≤200 tons, and a flatness of the mounting surface of ≤0.015mm/1000mm. It is suitable for metallurgical hot/cold rolling mills and ensures a rolling thickness tolerance of ±0.03mm.

◦ Wind Turbine Main Frame Foundations: Made of QT700-2 material, with a size of 5000×5000×1200mm, a load-bearing capacity of ≤300 tons, and an impact load resistance of ≥500kN. It is suitable for the installation of 3-10MW wind turbine main frames and ensures the long-term stable operation of wind power equipment (20-year service life).

• Reservation of Functional Interfaces:

The foundation components reserve equipment cooling water circuits (hole diameter 30-50mm, flow rate ≥20L/min) and hydraulic pipeline interfaces (φ20-φ40mm), which are suitable for the rolling mill lubrication system and the machine tool spindle cooling system. Sensor mounting holes (φ8-φ15mm) are reserved, which can be connected to vibration monitoring and temperature monitoring systems to monitor the working status of the foundation components in real time and provide early warning of deformation risks (automatic alarm when deformation exceeds 0.01mm).

Core Composition of the System

 

Component Category	Core Parameters and Configuration (Enhanced Characteristics of Large-Scale Foundation Components)
Cast Iron Machine Tool Bases	Material: HT350/HT400 gray cast iron; Size: Single block ≤6000×4000×1000mm, Spliced ≤10000×5000×1200mm; Precision: Mounting surface flatness ≤0.01mm/1000mm, Guideway surface straightness ≤0.008mm/1000mm; Load-bearing capacity: 50-80 tons; Structure: Box-type + cross ribs, reserved guideway mounting grooves, cooling water circuits, and sensor holes
Large-Scale Cast Iron Equipment Foundation Components	Material: QT600-3/QT700-2 ductile iron; Size: Single block ≤8000×4000×1500mm, Spliced ≤15000×6000×2000mm; Precision: Mounting surface flatness ≤0.015mm/1000mm, Hole positional tolerance ±0.02mm; Load-bearing capacity: 100-300 tons; Structure: Box-type + honeycomb ribs, reserved anchor holes, leveling holes, and shock absorption mounting grooves
Auxiliary Components	Heavy-duty adjustment pad irons (load-bearing ≤50 tons/set, adjustment range 0-20mm); High-strength splicing bolts (M40-M60, Grade 12.9); Air spring shock absorption modules (shock absorption efficiency ≥90%, load-bearing ≤100 tons/set); Large-scale levels (accuracy 0.01mm/m, used for installation and leveling)
Installation Accessories	Embedded steel bars (φ20-φ30mm, suitable for embedded installation); Expansion bolts (M30-M50, used for ground fixing); Sealing rubber strips (suitable for sealing at splicing joints to prevent dust/liquid intrusion)

Typical Industry Application Cases

1. 6m Heavy-Duty CNC Lathe Base: Used by a machine tool factory for a φ2000mm heavy-duty CNC lathe —— An HT400 base (6000×3000×800mm) is adopted, with a straightness of the guideway mounting surface of ≤0.008mm/6000mm. When bearing a 50-ton workpiece, the deformation is ≤0.003mm. The cylindricity error of processing a wind power main shaft (φ1800mm) is reduced from ±0.015mm to ±0.005mm, and the machine tool precision retention period is extended from 1.5 years to 4 years.
2. 200-Ton Rolling Mill Foundation Base: Used by a metallurgical enterprise for a hot rolling mill —— A QT600-3 foundation base (8000×4000×1500mm) is selected, with a mounting surface flatness of ≤0.015mm/1000mm and a hole system positional tolerance of ±0.02mm. It bears the entire 200-ton rolling mill. During the rolling process, the settlement of the foundation base is ≤0.005mm, the steel rolling thickness tolerance is reduced from ±0.1mm to ±0.03mm, and the product qualification rate is increased by 28%.
3. 10MW Wind Turbine Main Frame Foundation: Used by a wind power enterprise for the installation of a 10MW wind turbine main frame —— A QT700-2 foundation component (5000×5000×1200mm) is adopted, with an impact load resistance of ≥500kN. After installation, the levelness of the main frame is ≤0.005mm/m. The vibration amplitude of the foundation component during the operation of the wind power equipment is ≤0.002mm, the equipment failure rate is reduced by 40%, and the service life is extended to 20 years.

Core Competitive Advantages

• Barrier of Ultra-Large-Scale Manufacturing Capacity: It has the casting capacity for a maximum single-piece weight of 100 tons and a maximum size of 8000×4000mm. The splicing technology realizes an ultra-large-scale foundation component of 15000×6000mm, solving the pain point that traditional casting “cannot form ultra-large parts integrally” and meeting the demand of heavy-duty equipment for “overall structural stability”.
• Dual Advantages of Ultra-Load-Bearing Capacity and Long-Term Stability: The HT400/QT700-2 material has a load-bearing capacity of 50-300 tons. Combined with 90-120 days of aging treatment, the deformation of the large-scale foundation component in 10 years is ≤0.1mm/m, which is far better than that of the welded structure foundation component (deformation ≥0.5mm/m in 5 years). It reduces the loss caused by frequent calibration and shutdown of heavy-duty equipment (saving more than 300 hours per year).
• Controllable Machining Precision for Large Sizes: The composite machining of a 12m CNC boring and milling machine + large-scale grinding machine is adopted, with a large flatness of ≤0.015mm/1000mm and a splicing error of ≤0.005mm. It ensures the installation accuracy and operation stability of ultra-large-scale equipment and avoids equipment failures caused by “out-of-control precision of large sizes”.
• Flexible Ground Adaptability: It supports three installation methods: embedded, ground fixed, and shock absorption. It has low requirements on ground strength (C30 concrete is sufficient), and the installation cycle is 40% shorter than that of the welded structure. No complex ground transformation is required, reducing the equipment installation cost by 25%.
• Significant Cost-Effectiveness: The cost of large-scale cast iron foundation components is 30% lower than that of the welded structure (which requires splicing of multiple thick steel plates), and there is no cracking risk caused by welding stress. Maintenance is simple, and only one precision calibration