南钢股份关于公司主体信用等级上调的公告/Upload/files/%E4%BA%8C%E2%97%8B%E4%B8%80%E4%B8%83%E5%B9%B4%E5%9B%9B%E6%9C%88%E4%BA%8C%E5%8D%81%E4%B9%9D%E6%97%A5%20G17-055%20%20%E5%8D%97%E9%92%A2%E8%82%A1%E4%BB%BD%E5%85%B3%E4%BA%8E%E5%85%AC%E5%8F%B8%E4%B8%BB%E4%BD%93%E4%BF%A1%E7%94%A8%E7%AD%89%E7%BA%A7%E4%B8%8A%E8%B0%83%E7%9A%84%E5%85%AC%E5%91%8A.pdf