échelle automatique

Sub test()
Dim Nbre As Byte
With Worksheets("feuil1")
    For Nbre = 1 To .ChartObjects().Count
        .ChartObjects(Nbre).Activate
        With ActiveChart.Axes(xlValue)
            .MinimumScale = 55
        End With
    Next Nbre
End With
End Sub

Sub test2()
Dim Nbre As Byte
Dim Message, Default, MyValue
Message = "Entrez la borne minimum de l'échelle"
Default = "0"
MyValue = InputBox(Message, Title, Default)
With Worksheets("feuil1")
    For Nbre = 1 To .ChartObjects().Count
        .ChartObjects(Nbre).Activate
        With ActiveChart.Axes(xlValue)
            .MinimumScale = MyValue
        End With
    Next Nbre
End With
End Sub