Hammermills are in all facilities where grinding process takes place, especially in feed factories. They grind the product with blades called hammers. Hammers are subject to serious wear during grinding. Higher the rate of wear, higher the hammer circulation in factories and related spare-parts costs. This study focused on improving hammer performance by extending their durability. Firstly, current situation analysis was made. Samples were prepared from raw materials of S355 structural steel, 5630 boron alloy and 60SiMn5 spring steel; the most common hammer materials in market. Their heat-treated end products are also obtained and spectral and micro-structural analyzes with hardness tests were performed in laboratories. In line with results, decision was to continue working with 5630 steel. Alternatively, 50CrV4 spring steel and C45 mild steel were selected considering literature research, market availability, alloy element ratios and costs. Controlled heat treatment and surface hardening procedures were applied to samples made of these steels. Hammers were then tested in a wear mechanism designed to simulate the tribological system inside hammermill. Abrasive SiC based powders were used for accelerating the process. Hammers are weighed before and after the test with 1 mg precision scale, wear charts were created. Most successful samples were case-hardened C45 with cryogenic cooling. Considering procurement, manufacturing costs and equal grinding performance criteria; case-hardened 5630 samples came forward. As a result; more efficient, durable and cost-effective hammers were obtained. Acknowledgements: This paper was created thanks to studies made within the scope of TEYDEB 1501 project number 3200625 supported by TUBITAK.
Anahtar Kelimeler: Hammermill Hammers, Abrasion, Heat Treatment, Surface Hardening, Carbon Steels, Cost Analysis
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