Hello Fatih,
You can take a look at the Help Documentation: Chart for .NET > User's Guide > Image Export
To save an image in a file you can use SaveToFile method of NImageExporter class. The parameters of this method specifies the file name, the size, the resolution and the image format:
chartControl.ImageExporter.SaveToFile("c:\\temp\\temp.bmp", new NSize(200, 200), NResolution.ScreenResolution, new NBitmapImageFormat());
Nevron Chart support the export of the following image formats: BMP, PNG, JPEG, TIFF, GIF, PDF, SWF, XAML, SVG, EMF.