Inclusions in steel can alter the quality of the metal being produced, making it too brittle, non-ductile, or both. Since inclusions cannot be avoided, for the most part, the quantity and composition of the inclusion must be monitored to produce a top-of-the-line product.
Foreign particles make it into the steel mix either from outside sources, such as a lime additive, or internal sources, such as chemical reactions between the metal and the air. Oxides are some of the more common inclusions in steel, because of oxygen’s high reactivity. Calcium oxide, made from adding calcium carbonate – quick lime – to the steel mix, reacts quickly with other elements in the steel. Carbon monoxide shows up in abundance, and can be regulated with aluminum, creating alumina (Al2O3) instead. If both calcium oxide and aluminum oxide are both present, they react to form calcium aluminates, which reduce the amount of sulfur in steel.
With all these additives and reactions to keep track of, it is difficult to produce quality steel without insight into the inner workings of the compounds. Steelmakers must closely monitor all foreign particles that make it into the steel mix, and, to do this quickly and efficiently, have demanded an analyzer that can work on the shop floor. Aspex has responded to that demand with its Personal Scanning Electron Microscope (PSEM) with edx analysis combined with the Metal Quality Analyzer (MQA) software.
The MQA provides up-to-date inclusion composition directly on the shop floor. It quickly and accurately scans the sample with the electron beam, and, if the backscatter is dark enough to signify an inclusion, it automatically starts the inclusion identification process through use of the ‘rotating chord algorithm’ (RCA). After the inclusion is sized, the MQA uses the energy dispersive X-ray (EDX) to determine the elemental composition of the inclusion. This fully-automated analysis process is the fastest on the market, reaching scan speeds of up to 10,000 inclusions per hour.
Once the inclusions are identified, manufacturers can backtrack through the steel line to figure out where the foreign particles are coming from, and possibly take corrective action to eliminate the issue. By using the PSEM with MQA, steelmakers can reduce consumable consumption and increase energy savings far beyond the cost of implementation. The PSEM with MQA by Aspex is an all-in-one inclusion analyzing system, allowing manufacturers to have inclusions identified and elemental composition determined anywhere on the steel line.
Reference:
Aspex, http://www.aspexcorp.com/industries/metals.html
