You may see it on the attached movie.

I added some data to chart - one line.

After that I set lower bound to value > 0, so zero is not in shown range. I set autoranging to true, and force zero in range to true sequently. It doesn't affect. After that I add additional data, which has the minX value (minimal X argument) more then 0 again (not to affect on appearing of zero in range). After that option on zero in range forcing affected.

Code to reproduce:

import java.util.Arrays;
import java.util.Comparator;
import java.util.Random;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class JavaCharts extends Application {

    public static void main(String[] args) {
        launch(args);
    }
    NumberAxis axis1 = new NumberAxis(0, 100, 10);
    NumberAxis axis2 = new NumberAxis(0, 100, 10);
    LineChart testedLineChart = new LineChart(axis1, axis2);
    VBox vb = new VBox();

    @Override
    public void start(Stage stage) throws Exception {
        testedLineChart.setTitle("LineChart");
        testedLineChart.setStyle("-fx-border-color: darkgray;");

        ObservableList list = FXCollections.observableArrayList();
        int max = 100;
        int min = 30;

        for (int i = 0; i < 30; i++) {
            XYChart.Data newData = new XYChart.Data();
            newData.setXValue(new Random().nextDouble() * (max - min) + min);
            newData.setYValue(new Random().nextDouble() * (max - min) + min);
            list.add(newData);
        }
        Object[] array = list.toArray();
        Arrays.sort(array, new Comparator() {

            @Override
            public int compare(Object t, Object t1) {
                return (int) Math.round(((Double) ((XYChart.Data) t).getXValue()) - ((Double) ((XYChart.Data) t1).getXValue()));
            }
        });

        XYChart.Series serie = new XYChart.Series("serie", FXCollections.observableArrayList(array));

        testedLineChart.getData().add(serie);

        Pane pane = new Pane();
        pane.setPrefSize(600, 600);

        axis1.setLowerBound(min);

        ToggleButton tb1 = new ToggleButton("Autoranging");
        tb1.selectedProperty().bindBidirectional(axis1.autoRangingProperty());

        ToggleButton tb2 = new ToggleButton("Force zero in range");
        tb2.selectedProperty().bindBidirectional(axis1.forceZeroInRangeProperty());

        pane.setPrefSize(600, 600);
        pane.getChildren().add(testedLineChart);

        vb.getChildren().addAll(pane, tb1, tb2);

        Scene scene = new Scene(vb, 700, 700);
        stage.setScene(scene);
        stage.show();
    }
}


Just switch toggle buttons, to change autoRanging and forceZeroInRange properties' values.