レーザーメタル積層法により補修された循環ポンプインペラ材の信頼性評価

抄録

In thermal power generation, cavitation damage in the impeller of circulation pumps is a serious problem. In the past, such damaged part was replaced by brand new. Recently, advanced repairing process is required on site to reduce maintenance cost. The purpose of this study is to assess the reliability of the impeller material repaired by the laser metal deposition (LMD) method. For achieving this, a stainless cast steel material (SCS14), which is the same material as the actual impeller, is grooved to simulate cavitation damage, and this groove is then repaired by the LMD. The specimens were cut from the repaired part, and tensile and fatigue tests were conducted. As a result, it was confirmed that the tensile strength of the LMD repaired material was superior to that of the original material, and the fatigue strength was almost the same.