Fundamental sources of failures: Improper Manufacturing II — Lesson 3

This lesson covers the subject of Failure Analysis and Prevention, focusing on failures caused by improper manufacturing. It delves into the general and specific causes of component failure due to inappropriate manufacturing, such as welding procedures not being properly established or modified, non-clarity and ambiguity in manufacturing procedures, and inadvertent errors made by operators. The lesson also discusses the effects of these failures, such as reduced mechanical performance and increased sensitivity for crack nucleation. It further explores specific issues in processes like casting, welding, and machining, and how inappropriate conditions can lead to defects. For instance, it explains how metal-gas interactions at high temperatures can lead to slag inclusions and pores, and how alloy segregation can lead to metallurgical variations and increased corrosion tendency.

Video Highlights

01:37 - Explanation of how deficient manufacturing can lead to reduced mechanical performance and increased sensitivity for crack nucleation, which can cause premature failure.
07:22 - Discussion on the formation of residual stresses in casting due to improper gating and rising design, and how these stresses can promote cracking.
24:36 - Explanation of how different types of machining processes can lead to different structures and properties in the machined component.
33:29 - Examination of the effects of hot and cold deformation processes on the properties of the manufactured component.

Key Takeaways

- Improper manufacturing can lead to component failure due to various general and specific causes.
- Failures can result in reduced mechanical performance and increased sensitivity for crack nucleation and growth.
- Specific issues in processes like casting, welding, and machining can lead to defects.
- Metal-gas interactions at high temperatures can lead to slag inclusions and pores.
- Alloy segregation can lead to metallurgical variations, increased corrosion tendency, and hot tearing or solidification cracking.