硬度不够中途疲软是什么原因引起的

{"name":"\u786c\u5ea6\u4e0d\u591f\u4e2d\u9014\u75b2\u8f6f\u662f\u4ec0\u4e48\u539f\u56e0\u5f15\u8d77\u7684","type":"\u65f6\u5c1a\u7247","area":"\u6cd5\u56fd","year":"2019","lang":"\u56fd\u8bed","play":"\u84dd\u51494k","type1":"\u65f6\u5c1a\u7247"}