Why Do Welds Crack?
American Welding Society
Advancing the science, technology, and application of welding and allied joining and cutting processes worldwide.
If an ounce of prevention is worth a pound of cure when it comes to preventing weld cracking, then you can get a ton of advice from William F. Newell, Jr., P.E., P.Eng., IWE; Vice President, Euroweld, Ltd.
“When cracking occurs, I start diagnosing the problem asking such basic questions as, ‘Did you adhere to the WPS? Can you verify and document adherence?’ It’s important to validate the basics,” says Newell. “In my experience, for example, some of the most common causes of cracking are improper preheat, interpass and/or post-weld heat treatment temperatures. The WPS calls out details, but procedures such as traditional flame preheat are not an exact science.”
For the upcoming AWS Inspection and Expo Conference (IEC, Nov. 8 -10 in Austin, Texas), Newell will deliver an hour-long presentation that focuses on the fundamentals of why welds crack. His presentation covers topics such as:
·???????? Types of cracking
·???????? Joint design, groove geometry and bead shape
·???????? Materials issue
·???????? Service environment
·???????? Management issues
领英推荐
“An engineer’s design goal is to get the stress or load from one side of the weld to the other, but the weld design that gets qualified and how it gets used in operation can be very different,” says Newell.
“In my presentation, I detail a case study of cracking in a high-pressure steam line flow element. Local thermal expansion and geometric features were not fully accounted for in lab tests. Welding dissimilar materials, such as P91 to austenitic stainless, also created issues, and I’ll show how engineers and inspectors can be on the alert for them.”
Newell began his professional welding career in 1975 and has deep experience in power generation (nuclear, fossil fuels, and hydro-electric), industrial, manufacturing, heavy and highway construction, and auto racing welding applications. Among his many qualifications are positions as the former Chair of AWS D10 Committee on Piping and Tubing and Former Chair of ASME SCII/IX Subgroup on Strength of Weldments.
? “Many of my presentations dive into the details of code compliance and the science of welding, but for the IEC conference presentation, I wanted to be more of an engineering storyteller,” says Newell. “I will share examples from my career because I think they will be relatable to everyone who is inquisitive about weld cracking.”
Master Materials Eng., GE Plant Superintendent & GE Global (Fixer) 40+ Years!, GE Division Inventor of the Year 1980, NYS EHS Professional of the year, Basically Just ask Ray to fix it!!
1 年Thank goodness that you pasted this. I’m a retired materialist who has been totally involved with the welding process and in fact helped develop many welding processes back when it was not popular to say NO to many welding specks that were totally wrong! I was fired 17 times for telling the Engineers and Top Government so called experts to stop their insistence on welding processes requiring for us to due it this way!!! For all that know me only a few would stand with me. I was blessed to have been part of many really great Welding Engineers. That backed me up. Ray Gannon Retired totally
Journeyman Ironworker/Weldor
1 年Never never forget galvanized coverings on pipe and steel materials. Before welding the seams of either materials, clean one inch away for joining, 1)use heat with a good rosebud torch tip, 2) use stainless brush, rub thet galvanize liquid away.end pieces 3) use a standing desk until it's polished, last, make your perfect bevels. If you didn't do it correctly after it's been joined, just hit around the or on the weld, and it will crack sooner or later. I remember when you welding rod is almost done, cracks will become in the middle of the puddle
Mechanical Fitter
1 年Welding cracks ! if not done properly
Materials And Process Engineer at BLUE ORIGIN
1 年Always glad to see the true experts passing on knowledge. William F. Newell, Jr.