Table 8 Effect of heat treatment of an electroless nickel5 B coating on the fatigue strength of steel

Condition

Fatigue strength

MPa

ksi

Not coated

350

51

As-deposited

270

39

250 °C (480 °F) for 1 h

260

38

350 °C (660 °F) for 1 h

245

36

400 °C (750 °F) for 1 h

270

39

The reduction in fatigue strength produced by electroless nickel deposits is also affected by the thickness of the coating. Thicker deposits have the greatest effect on fatigue strength. This is illustrated in Fig. 19, which shows the reduction in strength of a carbon-manganese steel (St52, Werkstoff 1.0580) produced by different thicknesses of a 5% nickel coating (Ref 6).

Thickneos. mils

Thickneis, jiim

Fig. 19 Effect of coating thickness on the fatigue strength of a carbon-manganese steel

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