热等静压工艺对选区激光熔化成形 HastelloyX合金持久性能的影响

Effect of Hot Isostatic Pressing Process on Stress-Rupture Property of Hastelloy X Alloy by Selective Laser Melting

在4组工艺参数(1 100℃/100MPa/1h,1 175℃/160MPa/1h,1 175℃/160MPa/2h,1 175℃/100MPa/2h)下对选区激光熔化(SLM)成形Hastelloy X合金试样进行热等静压(HIP)处理,并在815℃、105MPa条件下进行了持久试验,研究了HIP工艺对试样显微组织和持久性能的影响。结果表明:HIP处理前试样的显微组织由细小柱状晶和树枝晶组成,经HIP处理后,晶粒长大,晶界上析出碳化物;在1 175℃下HIP处理后,试样的断后伸长率和断面收缩率均显著高于HIP处理前和在1 100℃下HIP处理后的,且显微组织和持久性能的各向异性减小;较长的HIP时间或较低的HIP压力会缩短试样的断裂时间,降低其断后伸长率和断面收缩率;当HIP工艺参数为1 175℃/160MPa/1h时,试样的持久性能相对较好,裂纹的消除效果也较好。

Selective laser melting ( SLM ) formed Hastelloy X alloy samples were treated by hot isostaticpressing ( HIP ) with parameters of 1 100 ℃ / 100 MPa / 1h , 1 175 ℃ / 160 MPa / 1h , 1 175 ℃ / 160 MPa / 2hand1 175℃ / 100 MPa / 2h , respectively , and then subjected to stress - rupture tests at 815 ℃ under 105 MPa.Theeffects of HIP process on microstructure and stress - rupture property were studied.The results show that beforeHIP treatment , the microstructure of the sample was composed of fine columnar crystal and dendrite.After HIPtreatment , the grains became larger and carbides precipitated at grain boundaries.After HIP treatment at 1 175℃ ,the elongation and reduction of area of the sample were higher than those before HIP treatment and after HIPtreatment at 1 100 ℃ , and the anisotropy of the microstructure and stress - rupture property decreased.Therelatively long HIP time or relativelylow HIP pressure decreased the rupture time , elongation and reduction of areaof the sample.When the HIP process parameters were 1 175 ℃ / 160 MPa / 1h , the stress - rupture property of thesample was relatively good , and the eliminating of cracks was relatively effective.