How should the mesh belt for a mesh-belt normalizing furnace be selected?

As the core load-bearing and conveying component of a belt-type normalizing furnace, the conveyor belt directly affects workpiece heat-treatment quality—specifically temperature uniformity and surface condition—as well as equipment operational stability and service life. Selection should be guided by three key dimensions: workpiece characteristics, process parameters, and environmental conditions, with particular emphasis on material high-temperature resistance, structural compatibility, and strength and wear resistance. The following is a systematic selection methodology:
I. Core Selection Dimensions: First Define the Scope of Requirements
1. Process Parameter Matching (Selection Basis)
Process Parameter Selection Influences Key Requirements
The heating temperature determines the temperature resistance grade of the mesh belt material: low temperature (≤600°C): standard carbon steel mesh belt; medium temperature (600–900°C): 304 stainless steel mesh belt; high temperature (900–1200°C): 310S/Inconel alloy mesh belt; ultra-high temperature (>1200°C): Hastelloy/ceramic mesh belt.
Holding time affects the thermal fatigue resistance of mesh belts. For long-term holding (＞4 hours per batch), use heat-resistant alloy mesh belts (such as 310S) to prevent high-temperature creep deformation in ordinary stainless steel mesh belts.
Cooling method affects the corrosion resistance and structural stability of the mesh belt: Water cooling / Mist cooling (in high-humidity environments): Select 316L or Inconel alloy (resistant to moisture-induced corrosion); Air cooling / Natural air cooling: Standard heat-resistant stainless steel is sufficient.
The mesh belt speed determines the belt’s strength and transmission efficiency. For high speeds (>3 m/min), select a belt with a large wire diameter and a dense mesh structure to enhance load-carrying capacity; for low speeds (<1 m/min), a conventional structure is sufficient.
2. Workpiece-specific adaptation (to prevent damage and contamination)
Workpiece Characteristics, Selection Influences, Key Requirements
Workpiece Materials: Prevent Metallurgical Reactions Between the Mesh Belt and the Workpiece Carbon steel/alloy steel workpieces: stainless steel or heat-resistant alloy mesh belt; titanium alloy/high-temperature alloy workpieces: Inconel or Hastelloy mesh belt (to avoid iron contamination); nonferrous metal workpieces: 316L stainless steel (to prevent oxidation contamination).
Workpiece Size and Weight Affect Mesh Belt Load Capacity and Mesh Design: Small/ Lightweight Workpieces (≤0.5 kg per piece): mesh aperture 5–10 mm, wire diameter 1.5–2 mm; Medium/ Mid-sized Workpieces (0.5–5 kg per piece): mesh aperture 10–20 mm, wire diameter 2–3 mm; Large/ Heavy Workpieces (>5 kg per piece): mesh aperture 20–30 mm, wire diameter 3–5 mm, or consider using a chain-plate mesh belt.
Workpiece surface requirements: Prevent the mesh belt from scratching the workpiece or leaving residual marks. For precision workpieces (such as automotive parts and electronic components): select plain-weave or twill-weave mesh belts with a smooth surface, or opt for mesh belts with a polished surface; for workpieces with no specific surface requirements: standard-structure mesh belts may be used.
Workpiece Shape: Prevent Workpieces from Falling or Getting Stuck. For irregular or small workpieces (such as fasteners and small stamped parts): mesh aperture ≤ 1/2 of the smallest dimension of the workpiece; for elongated or sheet-like workpieces: select a fine-mesh screen or a chain-plate conveyor belt to prevent slippage.
3. Environmental Condition Adaptation (Extending Service Life)
Environmental Conditions, Selection Influences, Key Requirements
Corrosive Environments: Prevent Oxidation and Corrosion of Mesh Belts Sulfur- or Chlorine-Containing Atmospheres (e.g., heat treatment of chemical components): 316L or Hastelloy mesh belts; Humid Cooling Environments: 316L or Inconel alloy mesh belts.
Oxidizing atmosphere affects the oxidation resistance of mesh belts. In strongly oxidizing environments (such as high-temperature heating in an air medium), 310S/Inconel 600 mesh belts—due to their high chromium content—exhibit excellent oxidation resistance.
Protective atmosphere to prevent reaction between the mesh belt and the shielding gas: hydrogen/nitrogen protection—310S/Inconel alloy mesh belts (excellent stability); vacuum environment—Inconel/titanium alloy mesh belts (low volatilization, no contamination).

II. Selection of Mesh Belt Material: Core Temperature and Corrosion Resistance
1. Comparison of Common Material Properties
Material Type Temperature Range (°C) Corrosion Resistance Strength and Wear Resistance Application Scenarios Cost Level
Carbon steel mesh belt ≤600 Poor (prone to rust) Moderate (high strength, moderate wear resistance) Low-temperature, non-corrosive, low-demand workpiece conveying Low
304 stainless steel mesh belt ≤850 Medium (resistant to weak acids, weak alkalis, and neutral environments) Medium (moderate strength, average oxidation resistance) Medium–low temperature, for ordinary workpieces (carbon steel, non-ferrous metals) Medium
316L stainless steel mesh belt ≤900 mm in height (acid- and alkali-resistant, suitable for saline and humid environments); medium to high strength (slightly higher than 304, with better wear resistance); suitable for medium-temperature, corrosive environments and precision workpieces; medium to high.
310S stainless steel mesh belt ≤1100°C (high resistance to severe oxidation and high-temperature corrosion), high (excellent resistance to high-temperature creep and good wear resistance), suitable for high-temperature (900–1100°C) and strongly oxidizing environments, high
Inconel 600/625 alloy mesh belt ≤1200 Extremely high (resistant to severe corrosion, high-temperature oxidation, and protective atmospheres) Extremely high (high high-temperature strength, wear resistance, and thermal fatigue resistance) Ultra-high temperature (1000–1200°C), precision alloy workpieces, vacuum / protective atmosphere Extremely high
Hastelloy mesh belt ≤1300 Extremely high (resistant to strong acids and bases, severe corrosion, and ultra-high-temperature oxidation) Extremely high (excellent ultra-high-temperature stability and wear resistance) Ultra-high temperature (>1200°C), highly corrosive environments, and workpieces made of special materials Extremely high
Ceramic mesh belt ≤1600 Extremely high (completely corrosion- and oxidation-resistant) Medium (high brittleness, poor impact resistance) Ultra-high temperature (>1300°C), highly corrosive, non-impact applications Extremely high
2. Avoiding Pitfalls in Material Selection
Avoid wasting resources on “high-performance at low temperatures”: For low-temperature applications below 600°C, there is no need to use 310S alloy mesh belts; 304 stainless steel is sufficient to meet the requirements.
Preventing damage due to “high temperature, low material performance”: For example, in a 1000°C high-temperature environment, using a 304 stainless steel mesh belt will result in rapid oxidation and creep deformation, necessitating an upgrade to 310S or Inconel alloy.
Incorrect selection for corrosive environments: In sulfur-containing, chloride-rich, or humid cooling environments, using a 304 stainless steel mesh belt will lead to pitting and rusting; therefore, 316L or Inconel alloy should be selected.

III. Mesh Belt Structure and Specification Selection: Tailored to Conveying Requirements
1. Selection of Mesh Belt Weaving Structure
Structure Type Characteristics Application Scenarios Key Parameters
Plain-weave mesh belt: smooth surface, uniform mesh openings, and excellent air permeability. Suitable for small and precision workpieces (such as electronic components and small fasteners) that require a scratch-free surface. Mesh opening: 5–10 mm; wire diameter: 1.5–2.5 mm.
Twill-weave mesh belt: high strength, excellent wear resistance, and moderate air permeability. Suitable for medium-sized workpieces of moderate weight (such as automotive components and stamped parts) in continuous-operation applications. Mesh aperture: 10–20 mm; wire diameter: 2–3 mm.
Herringbone woven mesh belt: strong load-bearing capacity, excellent anti-slip performance, and moderate air permeability. Suitable for large and heavy workpieces (such as large castings and thick plate components) in high-speed conveying applications. Mesh aperture: 20–30 mm; wire diameter: 3–5 mm.
Chain-plate conveyor belt (chain-and-net combination): extremely high strength, large load capacity, and excellent resistance to deformation. Ideal for ultra-heavy workpieces (>10 kg per piece), irregularly shaped workpieces, and applications prone to jamming. Plate thickness: 3–8 mm; pitch: 10–20 mm.
Welded wire mesh with small apertures (2–5 mm) and a smooth surface, designed to prevent small workpieces—such as powder metallurgy parts and miniature fasteners—from falling through. Wire diameter: 1–1.5 mm; aperture size: 2–5 mm.
2. Determination of Key Specification Parameters
Wire diameter and mesh size:
Wire diameter selection: Based on the workpiece weight, choose 1.5–2 mm for light-duty applications, 2–3 mm for medium-duty applications, and 3–5 mm for heavy-duty applications (a thicker wire diameter provides higher strength but reduces air permeability; therefore, a balance must be struck to ensure uniform heating).
Mesh selection: The mesh size shall be no greater than half the smallest dimension of the workpiece (to prevent the workpiece from falling through), while ensuring that the mesh area accounts for at least 30% (to guarantee adequate circulation of hot air within the furnace chamber and uniform heating).
Mesh belt width and length:
Width: 50–100 mm less than the effective width of the furnace chamber (to prevent friction between the edges of the mesh belt and the inner wall of the furnace), while fully covering the workpiece placement area (with a safety clearance of 100–150 mm on each side of the workpieces).
Length: Determined based on the total length of the furnace heating zone, insulation zone, and cooling zone, with a 5–10% allowance reserved for ease of installation and tensioning.
Tensioning method adaptation:
Short distances (≤5 m): Use a manually tensioned mesh belt (simple structure);
For long distances (>5 m): select an automatically tensioned mesh belt (to compensate for high-temperature creep elongation of the mesh belt and prevent deviation).

IV. Key Considerations for Selection in Special Scenarios
1. Precision heat treatment of workpieces (e.g., automotive components, electronic components)
Material: 316L/Inconel alloy (to prevent iron contamination and oxidative contamination);
Structure: plain or twill weave (with a smooth surface and no sharp protrusions); mesh belt surface polished to a roughness of Ra ≤ 0.8 μm.
Specifications: small mesh openings (5–10 mm) and fine wire diameter (1.5–2 mm), ensuring smooth workpiece conveyance without scratching.
2. High-temperature, strongly oxidizing environment (e.g., normalizing in a 1000°C air atmosphere)
Material: 310S/Inconel 600 alloy (high chromium content, excellent oxidation resistance, and superior high-temperature creep resistance);
Structure: Twill/herringbone weave (high strength, wear-resistant, and resistant to thermal fatigue);
Specification: Medium-coarse wire diameter (2.5–3 mm) to prevent breakage at high temperatures.
3. Corrosive environments (such as sulfur-containing atmospheres and water-cooled cooling)
Material: 316L / Hastelloy (acid- and alkali-resistant, resistant to moisture-induced corrosion);
Structure: encrypted or chain-plate type (reducing the contact area with corrosive media and enhancing structural stability);
Specifications: wire diameter ≥ 2.5 mm, mesh aperture ≤ 15 mm, to prevent strength reduction and subsequent breakage due to corrosion.
4. Conveyance of overweight/large workpieces (e.g., large castings, thick plate components)
Material: 310S/Inconel alloy (high high-temperature strength and excellent resistance to deformation);
Structure: chain-plate mesh belt (high load-bearing capacity, no risk of mesh openings falling off);
Specifications: plate thickness ≥ 5 mm, pitch ≥ 15 mm, and equipped with a high-strength chain drive (to prevent stretching and deformation of the mesh belt).

V. Post-Selection Verification and Maintenance Recommendations
1. Key Points for Selection Verification
Temperature resistance verification: the temperature rating of the mesh belt material must be 100–200°C higher than the actual heating temperature (to provide a safety margin and prevent failure at high temperatures);
Load Capacity Verification: The load capacity of the mesh belt per unit area (kg/m²) shall be ≥ total workpiece weight / placement area × 1.2 (allowing for a 20% safety margin);
Compatibility verification: The mesh belt material must not chemically react with the workpiece or the process atmosphere (e.g., titanium alloy workpieces should not be processed on carbon steel mesh belts to prevent iron contamination).
2. Maintenance Recommendations for Extending Mesh Belt Life
Regular cleaning: At the end of each shift, remove scale and workpiece residues from the mesh belt surface using dedicated tools to avoid scratching the belt.
Tension Adjustment: Regularly inspect the belt tension (sag ≤ 5 mm/m); in high-temperature environments, adjustments should be made more frequently as the belt is prone to creep and elongation.
Lubrication and Maintenance: Regularly grease the chain sections of the chain-plate mesh belt with high-temperature grease (with a temperature rating equal to or exceeding the belt’s operating temperature).
Avoid overloading: Strictly prohibit placing workpieces that exceed the weight or width limits to prevent stretching or breakage of the conveyor belt.
Gradual heating and cooling: Adhere to the principle of “stepwise heating and stepwise cooling” to prevent thermal stress-induced deformation of the mesh belt due to abrupt temperature changes.

VI. Common Selection Pitfalls and How to Avoid Them
Misconception Type Common Causes Avoidance Methods
Inadequate temperature resistance of materials: blindly selecting low-cost, standard-grade stainless steel while ignoring high-temperature requirements. Always select material based on the actual heating temperature plus 100°C; for high-temperature applications, 310S or Inconel alloy must be used.
Mesh openings that are too large or too small, without being matched to the workpiece dimensions, can result in workpiece drop-out or uneven heating. Mesh opening size should be no more than half of the smallest dimension of the workpiece, while ensuring that the mesh area accounts for at least 30%.
The wire diameter is too small, prioritizing breathability at the expense of load-bearing capacity. Select the wire diameter based on the workpiece weight: for heavy-duty workpieces, the wire diameter should be ≥3 mm, or consider using a chain-plate conveyor.
Improper selection for corrosive environments: Use 304 stainless steel in acidic, alkaline, or humid conditions; for severe corrosion scenarios, directly opt for 316L or Hastelloy to prevent rust and corrosion.
Neglecting protection-atmosphere compatibility: For hydrogen or vacuum environments, use standard stainless-steel mesh belts; for protective-atmosphere or vacuum applications, select Inconel or titanium-alloy mesh belts to prevent reactive contamination.
By employing the selection methods outlined above, precise matching can be achieved between mesh belts and mesh-belt normalizing furnace processes, as well as with specific workpiece requirements, thereby balancing heat-treatment quality, equipment stability, and service life. If a tailored selection solution is needed for particular workpieces—such as 45 steel fasteners or titanium-alloy components—or for specific process parameters—such as high-temperature normalizing at 1100°C under hydrogen protection—detailed parameters can be provided to facilitate further optimization.