Cold extrusion of metals is one of the most important manufacturing processes today and effectively involves forcing the material through the die at room temperature to create a continuous product of consistent cross-section.
Although there are minor variations, the 3 main extrusion process can be covered by forward extrusion, backward extrusion and upsetting which differ basically by the direction of the metal flow during the extrusion process.
Monthly Archives: September 2013
Production of Creep-Resistant Steels for Turbines: Part Two
Vacuum Arc Remelting (VAR) is a secondary melting process used in the production of metal ingots with a precise chemical and mechanical homogeneity for highly demanding applications. Ingots derived from the VAR process are typically utilized in the production of the critical components of jet engines and industrial gas turbines, as well as for military applications and heavy industry.
Casting Defects: Hot Tearing
One of the main casting defects is hot tearing or hot cracking, or hot shortness. Irrespective of the name, this phenomenon represents the formation of an irreversible failure (crack) in the still semisolid casting. Although in most works hot tearing is considered as a phenomenon linked to the inadequate compensation of solidification shrinkage by melt flow in the presence of thermal stresses, there are more factors that could be involved in the formation of cracks at supersolidus temperatures.
Production of Creep-Resistant Steels for Turbines: Part One
Due to its specific applications (elevated temperatures, lasting constant loads), steel for turbine blades is very complex as to its technology and quality, requiring a higher level of purity and continuous production process management.
In order to reduce the residual elements as low as possible to make high purity steels, the double slag process was improved by using electric arc furnaces and subsequently ladle refining furnaces.
Copper Bearing HSLA Steel: Part Two
The addition of copper in HSLA steels has been found to greatly benefit the strength levels of steels used for among other applications, offshore structures, pipelines and ship hulls.
In combination with copper additions, low carbon content is also essential for attaining the desired effects and during the last three decades, research has also extended to comparing the benefits of hot rolling versus quenching and tempering to make further gains in quality of the material properties.