## 4 Applications
### Overview
& Thermally induced material damage due to & \\  & & machining & [40; 41; 42] \\ \hline \multirow{2}{*}{4} & Surface hardened or nitrated & Hardening depth, depth profiles of hardness and & \\  & parts & residual stress, retained austenite content & [43; 44; 45] \\ \hline \multirow{2}{*}{5} & Steel grades & Classification of steel grades and microstructure & \\  & & variants & [46; 47] \\ \hline \multirow{2}{*}{6} & Cast iron & Residual stress, cementie content, primary chill, & [48; 49; 50] \\  & & microstructure gradient & \\ \hline \multirow{2}{*}{7} & Strip steel & Mechanical properties, microstructure features & \\  & & (texture, grain size) and residual stress & [51; 52] \\ \hline \multirow{2}{*}{8} & Heavy plate and forged parts & Mechanical properties, microstructure features, & \\  & parts & residual stress, hard spots & [52; 53] \\ \hline \multirow{2}{*}{9} & Cold formed steel sheets & Residual stress and spring back angle & [54; 55] \\ \hline \multirow{2}{*}{10} & Hot formed steel sheets & Mechanical properties of steel, coating thickness, & \\  & & resistance spot weld size & [56; 57] \\ \hline \multirow{2}{*}{11} & Electrical steel & Inspection of cut edges; cutting quality & [57; 58] \\ \hline \multirow{2}{*}{12} & Miscellaneous & Hydrogen-induced embrittlement, fatigue, & [59; 60; 61; 62] \\  & toughness, notch impact strength, creep damage & [63; 64; 65; 66; 67; 68; 69; 70; 71; 72; 73; 74; 75; 76; 77; 78; 79; 80; 81; 82; 83; 84; 85; 86; 87; 88; 89; 90; 91; 92; 93; 94; 95; 96; 97; 98; 99; 100; 101; 102; 103; 104; 105; 106; 107; 108; 109; 111; 112; 113; 114; 115; 116; 117; 118; 119; 120; 121; 122; 123; 124; 125; 126; 127; 128; 129; 130; 131; 132; 133; 134; 135; 136; 137; 138; 139; 140; 141; 142; 143; 144; 145; 146; 147; 148; 149; 150; 151; 152; 153; 154; 155; 156; 157; 158; 159; 160; 161; 162; 163; 164; 165; 166; 167; 168; 169; 170; 171; 172; 173; 174; 175; 176; 177; 178; 179; 180; 181; 182; 183; 184; 185; 186; 187; 188; 189; 190; 183; 187; 188; 189; 191; 200; 201; 202; 203; 204; 205; 206; 207; 208; 209; 207; 209; 211; 208; 201; 209; 212; 213; 214; 22; 2215; 226; 227; 228; 229; 230; 231; 232; 233; 234; 235; 236; 237; 238; 2 determine the depth-profiles of hardness, residual stress, and retained austenite in surface-hardened components [43; 44; 45]. The classification tasks can also be solved with 3 MA [46; 47]. Besides steel, cast iron is another material that can be characterized with 3 MA [48; 49; 50]. Section 4.2 describes the 3 MA applications on strip steel in detail [51; 52]. For thin strip, heavy plate, and large forged steel components, 3 MA is mainly used to determine the parameters of the tensile test, e.g., tensile strength Rm and yield strength Rp0.2 [52; 53]. In further processing, when the steel sheets are cold or hot formed, 3 MA is used for determining the mechanical properties and also the residual stress or spring back angle [54; 55; 56; 57]. An interesting application of 3 MA is the determination of electromagnetic properties (e.g., iron losses, maximum induction) in electrical steel, because 3 MA is able to locally determine these properties, which is not possible with Epstein frames, etc. [57; 58]. Furthermore, 3 MA can be used to characterize hydrogen-induced embrittlement, fatigue, toughness, notch impact strength, and creep damage in steel [59; 60; 61].