论文部分内容阅读
研究了K18铸造高温合金的热等静压(HIP)密实化。含有内部孔隙(缩孔和显微疏松)的铸件在热和气体压力的同时作用下,通过变形-闭合-扩散过程,内部孔隙能够完全闭合,并得到致密铸件。在12kgf/mm~2气体压力下,在1140～1210℃和1～3h范围内,孔隙闭合的程度是温度和时间的函数。HIP能够引起铸件显微组织的改变,但是,能够通过HIP后的热处理加以改善。HIP和随后的热处理明显地改善了铸件的强度、塑性和高周疲劳性能,而不降低其他性能。HIP也明显地减轻了铸件内枝晶间的元素偏析。
The hot isostatic pressing (HIP) densification of K18 cast superalloy was investigated. Castings containing internal porosity (shrinkage porosity and microscopic porosity) can be completely closed by a deformation-closure-diffusion process under the simultaneous action of heat and gas pressure, resulting in dense castings. At 12 kgf / mm ~ 2 gas pressure, the extent of pore closure is a function of temperature and time at 1140-1210 ° C and 1-3 h. HIP can cause changes in microstructure of castings, but can be improved by heat treatment after HIP. HIP and subsequent heat treatment significantly improve the strength, ductility and high-cycle fatigue properties of the castings without sacrificing other properties. HIP also significantly reduces elemental segregation between dendrites in the castings.