3.5.4.3 Design Rules for Parts Made From Open Die Forgings

1. Where material properties are critical, it is important to specify the required properties in all directions. This includes tensile strength, yield strength, ductility and impact toughness. The open die forger will design the forging process to develop grain flow that will optimize the properties. Otherwise the forging will be designed so that the grain flow follows the final contour of the forging.
2. In view of the end use of the product, specify the nondestructive testing methods to be employed and acceptable methods for employing them.
3. Open die forging can be employed for a wide range of shapes. For example, non-symmetrical shapes may be forged. Hollow shells can be forged by combinations of operations such as cogging, upsetting trepanning and punching, then mandrel forging. The ball valve housing shown in Figure 3-20 illustrates the shape capability achievable by open die forging.
   
   
   

   Figure 3-20 This ball valve housing illustrates the shape capability of the open die forging process .

4. Be sure to spell out where any prolongations for testing should be located.