This code will help you automatically save your charts as .png files on the server:

using System.Drawing;
using Nevron.GraphicsCore;
using Nevron.Chart;
using Nevron.Chart.View;
using Nevron.ReportingServices;

namespace MyNamespace
{
                /// <summary>
                /// Sample class
                /// </summary>
                public class MyClass
                {
                                /// <summary>
                                /// Main entry point
                                /// </summary>
                                /// <param name="context"></param>
                                public static void RSMain(NRSChartCodeContext context)
                                {
                                                using (NChartRasterView view = new NChartRasterView(context.Document, new NSize(400, 300), NResolution.ScreenResolution))
                                                {
                                                                using (NRasterImage image = view.RenderImage(new NPngImageFormat()))
                                                                {
                                                                                image.SaveToFile("c:\\chartimage.png", new NPngImageFormat());
                                                                }
                                                }
                                }
                }
}