Weld Failures - Part I
by, Dr. Jesse A. Grantham, Forensic Welding Engineer
The following article initiates a three-part series of topics for The Welding Leader (TWL) audience. There are many ways to write about “Weld Failures”. The perspectives presented in the following parts address different points of view of the Owner, Welds and the Forensic Welding Engineer.
Weld failures are the result of decisions and occasionally random accidents. A weld failure means a weld that does not meet the Owner’s expectations. Many weld failures are more related to company politics than welding metallurgy.
Every weld is the result of someone’s deliberate choices about design, materials, process and inspection. It is just that straight forward. When any one of these four key elements does not meet the Owner’s expectations, the costs for the project increase and welds unable to meet the Owner’s needs are considered failures.
The Owner of the project is not expected to be familiar with the key elements for a successful weld. It is normal for the Owner to be concerned about the project budget, completion schedule and return on investment. Welds are a means to those ends.
There is a reason for every type of weld. Welding and welds are expensive. There are elements of cost, risk and danger associated with all aspects of a weld and welding processes.
The behavior of welds used in commercially available steels can be predicted. When a weld failure occurs, managers need to be aware of the cold facts about the weld failure. Of course, it is more intriguing to conduct routine meetings about “why” a weld failed and whose fault it was, rather than to provide inspection and training to avoid weld failures.
Owners don’t really care about the metallurgy of why a weld failed. The Owner wants to know who is going to pay for the failure. Weld failure analysis experts don’t agree with each other about welding, welds, metallurgy and the root cause of a failure. Also, when the owner receives responses from several experts about a weld failure, it is not surprising that the outcomes tend to favor of each expert’s employer. When a dispute occurs, each side should hire their own forensic welding engineer to assess and opine on the reasons for the weld failure.
One test is worth a thousand expert opinions. Owners are reluctant to pay for testing and inspections before, during and after welding, until a weld fails. There are many bits of practical information that are not found in handbooks or taught in classrooms that are causes for a weld failure. Practical knowledge from inspection reports and experience in the shop contribute to the necessary probing for the truth. These are the working tools for the success of a Forensic Welding Engineer.
Forensic investigations of weld failures, materials, products or components that do not operate or function as intended are the cause of personal injury or damage to property. The Forensic Welding Engineer must have background, experience, training and education in welding. Real-time experiences as a Professional Engineer, Certified Welding Inspector and accomplished Nondestructive Testing expert provide a solid base to successfully address and solve weld failures.
Weld failures are the result of operator error, equipment malfunctions or natural disasters. To reduce costs the designer selects improved steel alloys, prequalified weld designs and service life extension features for extended service life. The purpose of a Forensic Welding Expert investigation is to locate the causes for a weld failure with an objective view that will improve performance or life of a component or to assist in a dispute to determine the cause of an incident.
Owners, supervisors and attorneys can surf the internet for hours and find many ideas and perhaps individuals who hold themselves out to be welding experts. Several differences between a professional and amateur are recognition by peers, life experiences, engineering ethics and proven objectivity in testimony.
How does an Owner with a weld failure select an expert? The Owner locates a Forensic Welding Engineer by referrals and memberships in professional groups. The Owner must trust the expert’s record of unbiased and objective testimony about past weld failures.