improper repair meaning in English

非正常修理
修补不良

After implementing the said measures , tube - burst ratio due to over - temperature of the heating surface has reduced from 34 . 8 % to 15 % , occurrence ratio of said leakage accidents due to improper repairs has also greatly decreased , but leakage times resulting from welded defects and material quality of the heating surface are enhanced obviously
实施后，受热面超温爆管比例从34 . 8 %下降至15 % ，因检修不良而造成的“四管”泄漏发生率也有大幅下降，但因焊接缺陷和受热面材质造成的泄漏次数却明显上升。