In the smelting process, metal elements were due to their oxidation and reduced, they are the degree of oxidation of many, not only with the size of its affinity to oxygen on the outside, and the elements in the alloy liquid concentration (activity), the formation of the oxides of the nature, and the temperature factors. In general, the oxygen affinity of the elements of a greater loss, aluminum, magnesium, boron, titanium and zirconium and other oxygen affinity is very strong; carbon, silicon, manganese, etc. Second, iron, cobalt, nickel, copper and lead, etc.. So in the melting alloy of oxygen affinity strong elements will be preferential oxidation "caused by the loss; on the contrary, those elements that the oxygen affinity of weak can relative be" protection "and the loss is less.
After smelting, an element in the chemical composition of the alloy is increased or decreased due to oxidation loss, which should be regarded as the relative loss of the matrix metal elements. Relative loss elements of the content will be reduced, known as "burning"; loss is relatively small elements, content will increase, called "burning increased"; to the chemical composition of the correct control of the melt, in the selection of metal charge, taking into account changes in the melting, in each element additions on the corresponding compensation.
In the actual smelting, alloy elements in the burning rate, but also by the quality of raw materials, flux and slag, technical operation, especially the influence of properties of the oxide formation.