Abstract: A forging steel has a dissolved Mg concentration within the range of 0.04-5 ppm by mass and a dissolved Al concentration within the range of 50-500 ppm.

Abstract: It is possible to generate a desirable form (soft, pliable) of sulfide inclusions in magnesium-treated case irons. Thermodynamically, MnS and MoS2 are not stable in the presence of magnesium. However, by adding magnesium to a cast iron melt containing manganese sulfide/molybdenium sulfide as late as possible, and preferably when the molten cast iron has been dispensed into the mould, such sulfide inclusions may be preserved in magnesium-treated cast iron. Alternatively, said cast iron can also be formed by adding said sulfides directly to the iron after the magnesium reaction has taken place and an in situ equillibrium has been established between magnesium, oxygen and sulfur. Another option is to begin with a sulfur content in excess of the stoichiometric amount required to combine with the added magnesium, thus ensuring an amount of left-over sulfur to promote the formation of the desired sulfide inclusion.

Abstract: A cast steel with excellent workability, characterized in that not less than 60% of the total cross section thereof is occupied by equiaxed crystals, the diameters (mm) of which satisfy the following formula: D<1.2X1/3+0.75, wherein D designates each diameter (mm) of equiaxed crystals in terms of internal structure in which the crystal orientations are identical, and X the distance (mm) from the surface of the cast steel. The cast steel and the steel material obtained by processing the cast steel have very few surface flaws and internal defects.

Abstract: The invention relates to a process for producing nodular cast iron with a high number of graphic nodules. This process comprises the following steps: preparing molten base iron for wasting castings of nodular cast iron; adding Mg to the molten base iron; inoculating the casting stream with a first inoculant when casting the cast iron into a casting mold. According to the invention, between the addition of the Mg and the inoculation of the casting stream, a preliminary inoculation using a further inoculant is carried out as an additional step. The invention also relates to a casting obtained by using this process.