Abstract：718Plus alloy bars for high pressure turbine case of Leap engine was processed into ring forgings by forging, ring rolling, heat treating and machining. During the ultrasonic flaw detection, it was found that there were several abnormal indications inside the forgings. The tests of metallographic inspection and mechanical property of the forging near the defects were conducted. Moreover, the sample was polished stepwise (0.1 mm) to display the defects. Then the defects were analyzed by optical microscopic observation and EDS. The results showed that the processes of forging and heat treatment were normal. The morphology and chemical composition analysis indicated that the defects were slag inclusion defects in smelting of nickelbased 718Plus alloy. It belonged to metallurgical defects.
2021, Vol. 39 
