Placas de Impacto | Peças para Britador HSI | ATF

Impact Plates: Secondary Wear Protection for HSI Crushers

Impact plates (also called aprons, breaker plates, or impact curtains) form the stationary crushing surfaces inside HSI crushers. Material ejected from the rotor at high velocity strikes these plates, causing secondary size reduction and shape improvement. The angle, position, and material condition of impact plates directly influence product gradation, crusher efficiency, and overall operating costs. These components are manufactured to ASTM A128 for manganese variants and ASTM A532 for high-chrome compositions. Correct plate geometry ensures proper material trajectory within the chamber, preventing recirculation of oversize particles that increases energy consumption and accelerates wear on other components. Plates are available in thicknesses ranging from 40 mm to 120 mm depending on the crusher model and chamber position.

Unlike blow bars that absorb direct high-velocity impacts, impact plates receive material that has already been partially reduced by the rotor. This shifts the dominant wear mechanism from pure high-energy impact to a combination of abrasion and lower-energy impact, with the ratio depending on chamber position. Primary plates closest to the rotor experience roughly 60% impact and 40% abrasion, while tertiary plates see predominantly abrasive sliding contact. Material selection must account for this gradient. Manganese steel grades (Mn14Cr2, Mn18Cr2) conforming to ASTM A128 are preferred for primary positions due to their work-hardening capacity under impact, while high-chrome irons per ASTM A532 Class III Type A deliver superior abrasion resistance in lower positions where impact energy is insufficient to trigger manganese work-hardening.