Controlling the particle size distribution of steel maru for ferrous metal products is crucial for ensuring consistent surface treatment and processing results. The uniformity of particle size distribution directly affects the impact energy transfer efficiency of steel maru during processes such as shot peening and polishing. Excessive particle size deviation leads to uneven surface treatment, and may even cause localized excessive wear or incomplete cleaning. Therefore, a comprehensive approach is needed across seven dimensions: raw material selection, production process control, particle size detection and grading, environmental control, dynamic adjustment of process parameters, finished product storage and transportation, and a quality traceability system.
Raw material selection is the foundation of particle size control. The raw materials for steel maru of ferrous metal products are typically scrap steel and special alloys. Magnetic separation is used to remove impurities such as iron filings and sand, followed by sieving to remove excessively large or small particles, ensuring uniform initial particle size. If heterogeneous particles are mixed into the raw material, they will form abnormal particle sizes during subsequent processing, disrupting the overall distribution stability.
Production process control is the core of particle size control. Steel Maru production often employs centrifugal atomization, where molten metal is flung out by a high-speed rotating atomizing disc, forming droplets that then cool and solidify. During this process, parameters such as atomization pressure, molten metal flow rate, and cooling rate directly affect droplet size, thus determining the initial particle size. For example, increasing atomization pressure reduces droplet size, while decreasing the cooling rate may cause particles to collide and agglomerate, forming coarse particles. Therefore, the optimal combination of process parameters must be determined experimentally based on the target particle size range and strictly monitored during production.
Particle size detection and grading are crucial for ensuring the distribution range. The detection stage commonly uses sieving and laser particle size analysis: sieving separates particles using multiple layers of standard sieves and calculates the mass percentage of each range, suitable for products with a wide particle size distribution range; laser particle size analysis utilizes the scattering characteristics of laser light by particles to generate distribution curves, accurately characterizing the distribution of fine particles. The grading process uses a multi-stage sieve combination with a reasonable sieve aperture sequence to separate products within the target particle size range, returning overly coarse or fine particles for reprocessing. For particle size fluctuations, classification efficiency can be optimized by adjusting sieving speed and amplitude, or airflow classification technology can be used to assist in the separation of fine particles.
Environmental control is crucial for particle size stability. Constant temperature and humidity must be maintained during testing to prevent samples from becoming damp or agglomerating, which could affect the accuracy of results. Dust concentration in the production environment must be controlled to prevent particles from breaking or sticking together during processing or transportation. For example, high humidity can cause particle surfaces to absorb moisture, forming micro-agglomerates and altering the actual particle size distribution.
Dynamic adjustment of process parameters is an effective means of addressing particle size deviations. Regular sampling and testing are necessary during production, and process parameters should be adjusted based on the results. If the particle size is found to be too coarse, the atomization pressure can be appropriately increased or the molten metal flow rate reduced; if the particle size is too fine, the atomization pressure should be reduced or the cooling intensity increased. Furthermore, real-time data feedback through an online particle size monitoring system allows for closed-loop control of process parameters, further improving particle size stability.
Particle size segregation must be avoided during finished product storage and transportation. Dedicated containers should be used for storage to prevent particle compaction and stratification of coarse and fine particles. During transportation, loading and vibration intensity must be controlled to prevent particle breakage or agglomeration due to collision. For example, severe vibration during transportation may cause fine particles to fill the gaps between coarse particles, resulting in a narrower overall particle size distribution.
A quality traceability system is the long-term guarantee for particle size control. By establishing a full-process traceability system for raw material batches, production parameters, and testing data, the causes of particle size deviations can be quickly located, and production processes can be optimized. For example, if a batch of products exceeds the particle size standard, the traceability system can be used to investigate key factors such as raw material batches and atomization pressure fluctuations, providing a basis for improvement in subsequent production.
