Materials & Welding

Background Cast iron is difficult, but not impossible, to weld. In most cases, welding on cast iron involves repairs to castings, not joining casting to other members. The repairs may be made in the foundry where the castings are produced, or may be made to repair casting defects that are discovered after the part is machined. Mis-machined cast iron parts may require repair welding, such as when holes are drilled in the wrong location. Frequently, broken cast iron parts are repaired by welding. Broken cast iron parts are not unusual, given the brittle nature of most cast iron. While there are a variety of types of cast iron, the most common is gray cast iron, and these guidelines are directed toward this type of material. A few facts about cast iron help in understanding the welding challenges. Cast iron typically has a carbon content of 2% - 4%, roughly 10 times as much as most steels. The high carbon content causes the carbon to form flakes of graphite. This graphite gives gray ca...

What you should know about welding aluminum. In recent years, the use of aluminum in manufacturing has become more prevalent because of its light weight and other attributes that make it an attractive alternative to steel. In fact, the aluminum welding market is expected to grow at a rate of 5.5 percent annually based primarily on the assumption that the automotive industry will continue to increase its use of aluminum. But, those experienced in the welding of steel will find aluminum to be a different breed – the normal welding characteristics of steel don’t always apply to aluminum. For example, aluminum’s high thermal conductivity and low melting point can easily lead to burnthrough and warpage problems if proper procedures are not followed. In this article, we will first take a look at various alloying elements and how they affect aluminum; then we will turn our attention to welding procedures and the parameters that will create the best quality weld. Lastly, we will examine some...

Answers from a survey of industry leaders give valuable feeedbackon the state of welding for the year 2000 and beyond. by Andrew Cullision and Mary Ruth Johnson The pulse of the welding community beats strongly heading into the 21st century and overall projections for the future are generally optimistic, but a few gray clouds roam the horizon. Those sentiments were expressed by respondents to a recent Welding Journal survey. To get a firm feel for that pulse of present and future conditions in the world of welding, the Editors queried AWS Sustaining Member companies, which include producers of a variety of welded products, providers of research and design services and manufacturers of welding equipment, consumables and accessories. The Editors would like to thank all those who took the time to put down their thoughts and ideas on paper. The responses were diverse, direct and, most of all, very interesting. Those questions and a summary of their answers are presented below. Do you beli...

Australian Stainless Steel Development Association (ASSDA) has outlined new and emerging stainless steel grades, which may be considered as alternatives to the traditional and widely known varieties. Users are seeking cost effective alternatives to both chromium and molybdenum austenitic 300 series grades. Austenitic 200 series, duplex stainless steels and ferritic grades can all be used instead of 304 and 316, if they are selected, designed, fabricated and used appropriately. The alloying elements in stainless steel contributing to corrosion resistance are chromium and molybdenum. Within each of the alternative groups there are grades with different corrosion resistance resulting from the chromium and molybdenum contents. The well-known austenitic 300 series grades contain the highest levels of nickel. According to ASSDA, these grades are austenitic despite their lower nickel because they have more manganese. Manganese is about half as effective in forming austenite as nickel, so for ...

John Kanzius happened upon the discovery accidentally when he tried to desalinate seawater with a radio-frequency generator he developed to treat cancer. He discovered that as long as the salt water was exposed to the radio frequencies, it would burn. The discovery has scientists excited by the prospect of using salt water as a fuel. Click here to view the video.  

Evidently, if a kilogram sits around doing nothing for too long, it begins to lose weight. Or rather, mass. The 118-year-old cylinder that is the international standard for the metric mass, kept tightly under lock and key outside Paris , has mysteriously lost as much as 50 micrograms. Made of a platinum-iridium alloy, the cylinder was cast in 1889 and measures 1.54 inches in height and diameter. Of course, it has lost mass only in relation to the 80 or so reference kilograms that exist around the world. It could be that, locked away as it's been for over a hundred years, it has remained the same and the others have gained weight. Click here for more information.  

The Newage B.O.S.S. (Brinell Optical Scanning System) significantly reduces operator influence and increases test speed. Available in standard or portable versions, with or without enclosures. To learn more, click here .