A small metallic particle that had contaminated a product line was brought to SI’s Materials Laboratory for analysis. The goal of the analysis was to identify the particle’s composition to help identify its original source. The particle was examined and…
Increasingly A Safety Concern as Coal Plants Cycle It is well known that conventional coal-fired utility boilers are cycling more today than they ever have. As these units have shifted to more of an ‘on-call’ demand they experience many more…
SH/RH Fireside Corrosion in Conventional Coal Fired Boilers Superheater/reheater fireside corrosion is also known as coal ash corrosion in coal fired units. Mechanism Coal ash corrosion generally occurs as the result of the formation of low melting point, liquid…
Determining a course of action once in-service damage is discovered often requires applying a multi-disciplinary approach that utilizes Nondestructive Examination (NDE), analytical techniques such as stress analysis, and metallurgical lab examination. Such was the case recently for a combined cycle…
As plants age, the need for inspection for service related damage to ensure unit reliability increases. There are several approaches that plants can take to reduce the risk of premature failures and proactively manage their DMWs. First is metallurgical sampling.…
By: Wendy Weiss, Tony Studer, P.E. While hydrogen damage is most often associated with severe gouging on the internal surface of a tube, it can occur in the absence of gouging. Structural Integrity received four waterwall tube sections from a…
In the world of metallurgical failure analysis, areas of interest on broken parts can be colorful or drab, three-dimensional or flat, and most importantly, very big or very small. A big part of failure analysis work is telling the story,…
By: Tony Studer Flexible metal hoses exist in numerous configurations, lengths, and diameters and have found a wide range of applications. In general flexible metal hoses are used in five types of applications: To correct for misalignment To provide flexibility…
By: Tony Studer Slag consists of molten, partially fused or re-solidified deposits on furnace walls and other surfaces exposed to radiant heat in coal and other solid fuel fired boilers. Explosive deslagging is one method of dealing with slag buildup;…
By: Wendy Weiss Structural Integrity Associates, Inc. (SI) was asked to examine a section of a burner gas ring from a boiler located at a chemical plant (Figure 1) and determine the cause of the corrosion and cracking. The approximately…
