Ductile dimple rupture (microvoid coalescence) caused by severe over load condition
Inclusion Rating/Raw Material Cleanliness:
Metals contain non metallic elements and compounds causing reduction in strength and many other issues including effecting the response to heat treatment of the metal. These non metallics refered to as inclusions are in some cases an aid toenhancing the machinability of the component. However, in most cases these non metallics reduce the engineering properties of the metal and contaminate the metal with non desirable constituents. We are able to prepare the specimens per standards and conduct cleanliness ratings or "dirt" count and rate the material with a simple table. In steels the inclusions are classified into 4 main groups listed as silicates, aluminas, sulfides, and oxides.
Non-metallic inclusions are chemical compounds of metals (Fe, Mn, Al, Si, Ca) with non-metals (O, S, C, H, N). Non-metallic inclusions form separate phases. The non-metallic phases containing more than one compound (eg. different oxides, oxide+sulfide) are called complex non-metallic inclusions .
Despite the small content of non-metallic inclusions in steel (0.01-0.02%) they exert significant effect on the steel properties such as: Tensile Strength, Ductility, Toughness, Fatigue Strength, Corrosion Resistance, Weldability, Machinability, and possibly other properties.
Oxides (including Alumina and Silicate)
FeO, Al2O3, SiO2, MnO, Cr2O3 etc.
Al2O3*SiO2, Al2O3*FeO, Cr2O3*FeO, MgO*Al2O3, MnO*SiO2 etc.
Sulfides
FeS, MnS, CaS, MgS, Ce2S3 etc.
Carbides
Fe3C, WC, Cr3C2, Mn3C, Fe3W3C etc.
Nitrides
TiN, AlN, VN, BN etc.
Carbonitrides
Titanium carbonitrides, vanadium carbonitrides, niobium carbonitrides etc.
Phosphides
Fe3P, Fe2P, Mn5P2
