1.What are the advantages of smaller diameter galvanized round bars in cutting?
High material utilization rate, suitable for precision parts: small diameter bars (such as diameter ≤ 10mm) have a small cross-sectional area and less material is removed during cutting, which is suitable for processing micro parts (such as electronic components, instrument accessories), which can reduce material waste and reduce costs.
High processing efficiency, suitable for high-speed cutting: small diameter bars have a small moment of inertia, and the machine tool can achieve a higher speed (such as more than 10000rpm). With a small feed rate, the processing time of a single part can be shortened, which is especially suitable for batch production.
More flexible clamping and positioning: Precision clamps such as spring chucks and collets can be used for rapid clamping, with high clamping accuracy, suitable for automated production lines. Small diameter bars are light in weight, more convenient to carry and load, and suitable for unmanned processing scenarios.
2.What are the precautions for cutting?
Insufficient rigidity leads to vibration and deformation: small diameter bars have poor rigidity, and are prone to bending vibration due to cutting force during cutting, resulting in deterioration of surface roughness, dimensional deviation, and even tool chipping.
The effect of galvanized layer on cutting: the galvanized layer (especially hot-dip galvanized layer) has high hardness, and there is stress at the junction with the substrate (steel), which is easy to occur during cutting.
Clamping slip and positioning error: the galvanized layer on the surface of small diameter bars is smooth, and ordinary three-jaw chucks are prone to slip during clamping, resulting in workpiece movement during processing and dimensional deviation.
Cutting heat concentration and workpiece deformation: small diameter bars have a small cross-sectional area, fast cutting heat conduction, and local temperature is easy to rise, resulting in: thermal oxidation of the galvanized layer (blackening of the surface), decreased corrosion resistance; dimensional deviation of the workpiece due to thermal expansion.
Chip entanglement and processing safety: small diameter bars are prone to produce thin and long ribbon chips when cutting, which entangle the tool or workpiece, resulting in: increased tool wear and even chipping; processing interruption, manual chip cleaning, affecting efficiency.
3.How to solve the problem of vibration and deformation caused by insufficient rigidity
Optimize the clamping method: use short cantilever clamping, or adopt a "double ejector" support structure to reduce the vibration of the cantilever end; for very fine bars (diameter <1mm), a hydraulic tailstock auxiliary support can be used.
Adjust cutting parameters: reduce cutting speed, reduce feed rate, and reduce cutting force; adopt a "multiple pass" strategy, with each cutting depth ≤0.2mm.
Use vibration-damping tools: choose carbide anti-vibration tool bars, or install dampers on the tool holder to suppress high-frequency vibrations.
4.How to solve the adverse effects of galvanized layer on cutting?
Tool material selection: Use coated tools to improve tool wear resistance; avoid using high-speed steel tools, and give priority to cemented carbide.
Application of cutting fluid: Use extreme pressure emulsion or mineral oil-based cutting fluid to enhance lubricity and reduce zinc chip adhesion; the cutting fluid flow rate must be sufficient to flush away chips and zinc chips in time.
Optimization of cutting angle: Increase the tool rake angle to reduce cutting resistance; set the back angle to 8°-10° to reduce friction between the tool and the workpiece.
5.What are the solutions for clamping slippage and positioning errors?
Special fixture: Use high-precision spring chuck, uniform clamping force, coaxiality ≤0.01mm; for extremely fine bars, "magnetic workbench + V-block" combination positioning can be used.
Surface treatment: The clamping part can be lightly polished in advance to increase friction, but it should be noted that it needs to be re-rust-proofed after polishing (such as applying anti-rust oil).