When selecting shot blasting and peening equipment for castings, it is essential to comprehensively consider factors such as casting characteristics, cleaning objectives, equipment performance, and cost-effectiveness. The following are the specific selection principles and key considerations:

I. Principle of Matching Casting Characteristics
Material and Hardness
High-hardness castings (such as alloy steels and ductile irons): Shot blasting equipment should be selected to utilize the impact force of high-velocity projectiles (steel shots or steel grit) for surface cleaning, thereby avoiding the excessive wear or surface damage that may result from sandblasting.
Low-hardness castings (such as gray cast iron and aluminum alloys): Sandblasting (using glass beads or ceramic beads) or shot blasting can be selected based on surface roughness requirements, with sandblasting offering better control over surface finish.
Shape and Dimensions
Complex-structure castings, such as engine cylinder blocks and turbine blades: require the selection of through-type or turntable-type shot blasting machines equipped with multi-angle nozzles or rotary fixtures to ensure thorough cleaning of concealed areas.
Large castings (such as machine tool beds and wind turbine tower sections): prioritize the use of continuous through-type shot blasting chambers, which support automated loading and unloading to enhance processing efficiency.
Small precision castings (such as automotive components): either track-type or drum-type shot blasting machines can be selected to reduce per-piece costs through batch processing.
Surface Defect Types
Adherent sand and oxide scale: Shot blasting equipment achieves higher efficiency than sandblasting by using high-velocity shot impact to strip them off.
Burrs and Flash: Abrasive blasting equipment, such as pressurized sandblasters, can more precisely remove localized defects while minimizing damage to the substrate.
Internal cavity cleaning: Equipment equipped with an internal-bore spray gun or vibration cleaning function must be selected, such as a vibratory finishing machine for auxiliary processing.
II. Cleaning Objectives and Process Requirements
Surface Roughness Control
Pre-coating surface preparation: The surface cleanliness shall meet Sa2.5 to Sa3 grade (according to ISO 8501-1). By adjusting the shot media size and blasting velocity, the shot blasting equipment can precisely control the surface roughness (Ra 3.2–12.5 μm).
Strengthening treatment: To enhance fatigue life, shot peening equipment should be selected, and a compressive residual stress layer on the surface can be achieved by controlling shot coverage (≥98%) and impact energy (as measured by the Almen intensity test).
Environmental and Safety Requirements
Dust Control: Prioritize equipment equipped with pulse-jet dust collection systems to ensure that emission concentrations do not exceed 10 mg/m³, in compliance with GB 16297.
Noise Control: Adopt low-noise designs, such as sound enclosures and vibration-isolating bases, to ensure that workshop noise levels do not exceed 85 dB(A).
Waste material recycling: Select equipment with high efficiency in separating shot media from dust and debris (such as air-separation classifiers) to reduce abrasive consumption costs.
Production efficiency requirements
Mass production: Select continuous-flow or rotary-table equipment, with a single-shift processing capacity of 5–20 tonnes.
Single-item, small-batch production: Opt for crawler-type or roller-type equipment, which feature short changeover times and flexible adaptability to multi-variety production.
III. Principles of Equipment Performance and Reliability
Quality of core components
Shot blaster: Choose a dual-disc or impeller-type shot blaster with a service life of over 8,000 hours to ensure uniform shot distribution.
Dust Collection System: Select a pulse-jet baghouse dust collector with a filter bag service life of ≥2 years and a filtration efficiency of ≥99.9%.
Conveyor system: Opt for wear-resistant chains or rubber tracks to reduce maintenance frequency.
Level of Automation and Intelligence
Automatic Control: Equipped with a PLC control system to enable real-time monitoring and adjustment of parameters, such as shot flow rate and spray gun angle.
Fault diagnosis: Select equipment with remote monitoring and early warning capabilities to reduce the risk of downtime.
Data traceability: Supports the recording of production data (such as processing time and shot consumption), facilitating quality traceability and cost analysis.
Maintenance and Operational Convenience
Replacement of wear parts: Opt for equipment with a modular design, such as quick-change shot-blasting wheel blades and filter bags, to minimize downtime.
Safety Protection: Equipped with safety doors, emergency stop buttons, light curtains, and other safety devices to ensure operator safety.

Shanchuan Holdings