August 2023 Volume 5

EQUIPMENT & TECHNOLOGY

Conclusion From simple beginnings the tool and die industry has come a long way, both in the sophistication of raw die materials and in the sinking of dies to serve the forging industry. The need to meet harsher and tougher service demands resulted in the use of alloying elements that helped tool steels last longer by preventing cracking in service and under cyclical elevated thermal conditions. High alloying, in turn, requires careful processing of tool steels as they are forged and/ or rolled. Generally, raw die blocks have been carefully inspected for hardness, grain size, and other metallurgical parameters after closely controlled thermal treatments have been applied. Forging dies have increased in accuracy, complexity, and size, all enabled by emerging technologies. These include CAD/CAM designs, which can be fed into versatile, multi-axis CNC machining centers capable of sinking dies for increasingly complex parts. Designs and coatings for cutting tools have enhanced material removal rates during machining, and improved laser scanning techniques have tightened tolerances by an order of magnitude. Dies can be coated to improve their service life (more production cycles). A coated die surface enhances its mechanical properties and improves the lubricity between the workpiece and the die surface. Carburization and nitriding are common die coating techniques.

Finally, exposure to cryogenic processes helps to transform austenite in the die material to martensite, thereby improving the tool material’s durability. Cryogenics can also enhance the formation of carbides in the steel and relieve residual stresses from the manufacture of the die material itself, as it was once solidified from its molten state.

Author Dean M. Peters has covered metal working markets, including the foundry, welding & industrial gas, heat treatment and forging industries for more than 30 years. His journalistic credentials are enhanced by his BS in metallurgical engineering, MBA in finance and a decade of experience in market research. He can be reached by e-mailing ForgeOpEd@gmail. com.

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