飞机结构用螺栓、销子、轴、接头、套筒、叉形件、活塞杆、壳体、弯管、耳环等许多零件,由于减重或内部需装配部件、内腔需充气体或液体介质等原因,不仅零件的外形复杂,往往还带有盲孔或内腔。这类零件在热处理时,由于高温加热中的氧化脱碳,冷却后盐、碱溶液的冷凝,在盲孔或内腔中将残存氧化皮或盐、碱杂质。受到几何形状的影响,采用热水、酸洗或吹砂方法难以清洗干净,造成内腔堵塞、腐蚀或有多余 Aircraft structure with bolts, pins, shafts, fittings, bushings, forks, piston rod, shell, elbow, earrings and many other parts, due to weight loss or internal components to be assembled, the cavity to be filled with gas or liquid medium And other reasons, not only the parts of the complex shape, often with blind holes or cavity. Such parts in the heat treatment, due to oxidation and decarbonization in high temperature heating, cooling salt, alkali solution condensation, in the blind hole or cavity will remain oxide or salt, alkali impurities. Affected by the geometry, the use of hot water, pickling or blowing sand method is difficult to clean, resulting in lumen congestion, corrosion or excess