QT Chart使用QValueAxis y轴坐标标题显示

使用QValueAxis设置了一个y坐标轴，添加了标题，但是标题朝向有问题，该怎么设置呢

这个是显示图片

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QValueAxis * m_cateAxis_X;
QValueAxis * m_cateAxis_Y;

//x 轴
    m_cateAxis_X = new QValueAxis;
    m_cateAxis_Y = new QValueAxis;
    m_cateAxis_X->setRange(0, 80);
    m_cateAxis_X->setLabelFormat("%d");
    m_cateAxis_X->setLabelsFont(QFont("宋体"));
    m_cateAxis_X->setTitleText("观测次数");

    m_cateAxis_Y->setLabelFormat("%d");
    m_cateAxis_Y->setRange(0, 10);
    m_cateAxis_Y->setTickCount(10);//网格线
    m_cateAxis_Y->setMinorTickCount(0);//网格线
    m_cateAxis_Y->setLabelsFont(QFont("宋体"));
    m_cateAxis_Y->setTitleText("电导率值");
    m_cateAxis_Y->setGridLineVisible(true);

    QPen axispen;
    axispen.setColor(QColor(0, 0, 0));
    axispen.setStyle(Qt::DotLine);
    axispen.setWidth(1);
    m_cateAxis_Y->setGridLinePen(axispen);


    setRenderHint(QPainter::Antialiasing);
    
    chart()->legend()->setVisible(false);//不显示图例
    chart()->setAxisX(m_cateAxis_X);
    chart()->setAxisY(m_cateAxis_Y);

请问该怎样设置出来跟下图效果呢
默认是居中的，该怎样设置下图效果呢

img