To reproduce:
public Form1()
{
    InitializeComponent();

    ScatterSeries series = new ScatterSeries();
    series.DataPoints.Add(new ScatterDataPoint(5, 5));
    series.DataPoints.Add(new ScatterDataPoint(4, 2));
    series.DataPoints.Add(new ScatterDataPoint(-1, 3));
    series.DataPoints.Add(new ScatterDataPoint(8, 4));

    radChartView1.Series.Add(series);

    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.Minimum = -10;
    horizontalAxis.Maximum = 10;
}
private void radButton1_Click(object sender, EventArgs e)
{
    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.DesiredTickCount = 20;
}