Failure Prevention

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Failure Prevention

  1. 1. Raymond F. Mignogna, MS, PE <ul><li>Metallurgical Engineering </li></ul><ul><li>Failure Prevention, </li></ul><ul><li>Investigation, Analysis </li></ul><ul><li>‘Don’t Let Bad Things Happen </li></ul><ul><li>To Good Materials’ </li></ul>
  2. 2. Failure Prevention <ul><li>Failure Prevention Starts With – </li></ul><ul><li>Materials Selection </li></ul><ul><li>Process Selection </li></ul><ul><li>Quality Assurance </li></ul>
  3. 3. <ul><li>Consequences of Failure </li></ul>Loss Due To Failure Low Medium High Susceptibility To Failure Low Medium High Prevention Efforts and Priority
  4. 4. More Failure Prevention Tools <ul><li>Design Reviews </li></ul><ul><li>Codes, Standards, Regulations </li></ul><ul><li>Failure Modes and Effects Analysis </li></ul><ul><li>Reliability – Safety Factors </li></ul><ul><li>Operation, Maintenance, Inspection </li></ul><ul><li>Lessons Learned </li></ul>
  5. 5. Materials Selection <ul><li>Evaluation of Candidate Materials </li></ul><ul><li>Evaluation of Material Conditions </li></ul><ul><li>Screening Studies </li></ul>
  6. 6. Process Selection <ul><li>Evaluation of Candidate Processes </li></ul><ul><li>Evaluation of Process Conditions </li></ul><ul><li>Process Capability Studies </li></ul>
  7. 7. Quality Assurance <ul><li>Application of Standards </li></ul><ul><li>Materials Test Method Selection </li></ul><ul><li>Test Method Development </li></ul><ul><li>Test Data Analysis </li></ul>
  8. 8. Common Failure Mechanisms <ul><li>Corrosion </li></ul><ul><li>Fatigue </li></ul><ul><li>Catastrophic Brittle Failure </li></ul><ul><li>Tensile or Compressive Overload </li></ul><ul><li>Lack of Coating Adherence </li></ul><ul><li>Lack of Joint Integrity </li></ul>
  9. 9. Failure Prevention Strategies <ul><li>Design Review for Failure Prevention </li></ul><ul><li>Have we examined the previous use of this material and process combination for the proposed application? </li></ul><ul><li>Have we considered previous instances of failure? </li></ul><ul><li>Failure Modes and Effects Analysis </li></ul><ul><li>Have we considered every possible failure scenario and devised an appropriate mitigation approach? </li></ul>
  10. 10. Design Process <ul><li>Step Purpose Output </li></ul><ul><li>Task Clarification Problem Definition Design Spec </li></ul><ul><li>Conceptual Design Generation, Selection Design Concept </li></ul><ul><li>Evaluation of Solutions </li></ul><ul><li>Embodiment Design Development of Final Design </li></ul><ul><li>Design Concept </li></ul><ul><li>Detail Design Definition of Every Manufacturing/ </li></ul><ul><li>Component in Shape Construction </li></ul><ul><li>and Form Instructions </li></ul>
  11. 11. Design Review <ul><li>Is (was) there a clear statement of the problem to be solved? </li></ul><ul><li>Is (was) there a set of requirements or constraints against which to evaluate proposed solutions? </li></ul><ul><li>Is (was) there a realistic project plan, acceptable to all parties? </li></ul><ul><li>Is (was) the design spec independent of solutions, or does (did) it include fictitious constraints? </li></ul>
  12. 12. Design Review (cont.) <ul><li>Has (was) the design spec circulated to all involved for comment and approval? </li></ul><ul><li>Was the design spec formally approved before conceptual design? </li></ul><ul><li>Where is the design spec? Who developed it? </li></ul><ul><li>Who approved it? </li></ul><ul><li>What changes were made? By whom? </li></ul><ul><li>Why? When? How? </li></ul>
  13. 13. Failure Modes & Effects Analysis <ul><li>Development Schedule FMEA Schedule </li></ul><ul><li>Conceptual Design Planning </li></ul><ul><li>Preliminary Design Functional Analysis </li></ul><ul><li>Detailed Design/Development Interface Analysis </li></ul><ul><li>Detailed Analysis </li></ul><ul><li>Design Verification/Validation Verify Analysis </li></ul><ul><li>Production/Use/Support Update Analysis </li></ul>
  14. 14. Project Example <ul><li>Material Selection </li></ul><ul><li>Selection of a specialty alloy for use in a high temperature sea water application. </li></ul><ul><li>Major Considerations: </li></ul><ul><li>Sea Water (Salt Exposure) </li></ul><ul><li>Temperature (Rate of Corrosive Attack) </li></ul><ul><li>Proposed Solution – AL-6X </li></ul>
  15. 15. Project Example <ul><li>Processing </li></ul><ul><li>Development of a coating process for corrosion protection and wear resistance. </li></ul><ul><li>Major Considerations: </li></ul><ul><li>High temperature, hot gas environment </li></ul><ul><li>High coating density required </li></ul><ul><li>Coating thickness of over .010” desired. </li></ul><ul><li>Proposed Solution – Thermal Spray Process </li></ul>
  16. 16. Project Example <ul><li>Quality </li></ul><ul><li>Verification of heat treatment of steel alloy. </li></ul><ul><li>Major Considerations </li></ul><ul><li>Many parts </li></ul><ul><li>Rapid testing speed required </li></ul><ul><li>Proposed Solution – ASTM Standards E-18 (Rockwell Hardness) and E-1994 (SAMPLING Plans) </li></ul>
  17. 17. Project Examples <ul><li>Failure Investigation and Analysis </li></ul><ul><li>Evaluation of a failed oil storage tank (galvanic corrosion). </li></ul><ul><li>Evaluation of corrosion of a stainless steel chemical vessel (high temperature exposure) </li></ul><ul><li>Investigation of corroded galvanized steel light poles (improper galvanizing process). </li></ul><ul><li>Investigation of erosion-corrosion of a copper alloy in a piping system (excessive flow rate for this alloy). </li></ul><ul><li>Evaluation of cracked steel dies for a metal products manufacturer (improper heat treatment). </li></ul>
  18. 18. FAILURE PREVENTION “ An ounce of prevention is worth a pound of cure.” – Ben Franklin www.mignogna.net [email_address] 352-638-2072

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