Shot Peening to Prevent Cracking in the Water Cooling Hole of Die-Casting Die

Author:  Y. Kobayashi, A. Matsui
Source:  Conf Proc 2014: ICSP-12 Goslar, Germany (pgs.463-469)
Doc ID:  2014121
Year of Publication:  2014
Abstract:  
Tensile stress is occurred on inside of water cooling hole of die casting die by cyclic heat stress. As a result, water cooling hole was broken by stress corrosion cracking and fatigue by cyclic thermal stress. The minimum diameter of water cooling hole is 3mm, the maximum hole depth is 300mm. Prevention of fracture on water cooling hole is tried that is induced residual stress by shot peening. In the previous experiment, 1500MPa residual stress is induced on inside of water cooling hole. Expanding of die life that was applied shot peening can be confirmed on actual production.