Materials Selection Most large metal structures are made from carbon steel-the world’s most useful structural material. Carbon steel is inexpensive, readily available in a variety of forms, and can be machined, welded, and formed into many shapes. This large statue by Pablo Picasso in front of the Chicago city hall is made from a special [...]
Hydrogen can cause a number of corrosion problems. Hydrogen embrittlement is a problem with high-strength steels, titanium, and some other metals. Control is by eliminating hydrogen from the environment or by the use of resistant alloys. Hydrogen blistering can occur when hydrogen enters steel as a result of the reduction reaction on a metal cathode. [...]
Galvanic Corrosion Galvanic corrosion is an electrochemical action of two dissimilar metals in the presence of an electrolyte and an electron conductive path. It occurs when dissimilar metals are in contact. It is recognizable by the presence of a buildup of corrosion at the joint between the dissimilar metals. For example, when aluminum alloys or [...]
Metals corrode because we use them in environments where they are chemically unstable. Only copper and the precious metals (gold, silver, platinum, etc.) are found in nature in their metallic state. All other metals, to include iron-the metal most commonly used-are processed from minerals or ores into metals which are inherently unstable in their environments. [...]
Overview Anodic Protection is a corrosion mitigation technique first introduced in the 1960′s in which the potential of an alloy is controlled relative to a stable reference potential in a range of values more positive or oxidizing than the corrosion potential that causes the corrosion rate to be depressed relative to that which would occur [...]
Over the past 30 years, pipefreezing for temporary pipe isolation has become the safest, cheapest and most effective method for allowing valve replacement and general pipework modifications. Fluid in the system no longer needs to be drained down, therefore valuable time can be saved and the costly process of refilling and venting can be avoided. Toxic [...]
The best way to understand the metallurgy of carbon steel is to study the ‘Iron Carbon Diagram’. The diagram shown below is based on the transformation that occurs as a result of slow heating. Slow cooling will reduce the transformation temperatures; for example: the A1 point would be reduced from 723°C to 690 °C. However [...]