3. THE DESIGN AND DEVELOPMENT OF PRODUCTS MADE FROM FORGINGS

This section presents a step-by-step process for designing a product to be made by forging. Some of the material in it is also presented more briefly in Section 2, Specifying and Purchasing Forgings. The repetition is intentional, making this a stand-alone section, which addresses the needs of those who design and develop products made from forgings.

The product to be designed may be totally new, or it may be redesigned or adapted from an existing application. In either case, the optimum process consists of the following eight steps.

1. Form a concurrent engineering team.
2. This is the best way to get maximum product development input in the critical early stages of design.
3. Establish the design parameters.
4. This step will eliminate materials and processes that are not suitable and focus on the ones that are.
5. Determine the cost drivers.
6. The manufacturer quotes the price, but the designer "designs in" nearly all of the cost.
7. Select the optimum process.
8. Several processes may work; selecting the optimum one requires knowledge of process tradeoffs.
9. Develop the optimum shape for the function and process.
10. The manufacturing process drives the product shape and may have more influence than does product function.
11. Develop the required properties.
12. Properties should be designed into the product — to stay.
13. Specify the correct heat treatment.
14. Heat treatment can significantly increase properties, although heat treatment may not be necessary in some cases, such as microalloy steels.
15. Prove the design.
16. Computer aided engineering and prototype testing are helpful steps in verifying product integrity, before investing in production tooling.

The following sections systematically develop each of the above steps:

Concurrent Engineering (3.1)
Design Parameters for Forgings (3.2)

• Service Loads
• Service Temperatures
• Corrosion Environment
  - Atmospheric
  - Galvanic
  - Stress corrosion cracking
• Interfacing Structural Components

Cost Drivers (3.3)

• Material
• Tooling Cost
• Manufacturing Cost
• Secondary Operations
• Quantities Produced

Process Tradeoffs (3.4)

• Comparison of Open Die, Impression Die, Rolled Ring and Cold Forging Processes
• Forging Processes Compared With Alternate Processes
  - Sheet Metal Stamping
  - Weldments
  - Foundry Casting
  - Investment Casting
  - CNC Machined Bar and Plate
  - Powder Metallurgy Processes
  - Reinforced Plastics and Composites

Designing Products Made From Forgings (3.5)

• Development of a Typical Shape
• Selecting a Forging Company
• Selecting the Optimum Forging Alloy
• Product Design Guidelines

Predicting, Developing and Maintaining Properties in Forgings (3.6)

• Physical Properties
• Mechanical Properties
• Developing and Maintaining Product Performance

Specifying Heat Treating (3.7)

• Steel
  - Annealing Processes
  - Hardening Treatments
• Stainless Steels
• Aluminum Alloys
• Titanium Alloys
• Heat Resistant Alloys

Prototyping (3.8)