摘要
对比了热等静压(HIP)+热挤压(HEX)+等温锻造(IF)制备的第三代镍基粉末高温合金FGH4113A经不同热处理后,在应力、应变控制条件下的疲劳断裂特性,结果表明:使用细粉经挤压锻造制备的FGH4113A合金晶粒度达到12级以上,未见PPB缺陷,夹杂物尺寸得到有效控制。合金经亚固溶热处理晶粒度保持在12级左右;合金经过固溶热处理,随着一次γ'的大量溶解,晶粒度长大至7.8级左右。650℃应力控制和700℃/0~0.8%应变控制条件下,过固溶热处理试样中夹杂型疲劳源占比均在15%以下;亚固溶热处理试样中夹杂型疲劳源占比达到85%以上,但疲劳源均为小尺寸夹杂物,试样的疲劳寿命未见降低;700℃大应变(总应变幅大于等于1.0%)控制条件下,试样疲劳源不再受热处理工艺影响,疲劳裂纹只萌生于表面,且位于试样表面的夹杂物对疲劳裂纹最敏感。
The fatigue origins and fracture characteristics under different test conditions and heat treatments of a third generation nickel-based powder metallurgy superalloy FGH4113A prepared by hot isostatic pressure(HIP)+hot extrusion(HEX)+isothermal forging(IF)were studied.The results show that the mean grain size of FGH4113A alloy prepared by extrusion and forging with fine powder reaches grade 12 or more,no PPB defects are found,and the size of inclusions is effectively controlled.The mean size of the alloy is maintained at about grade 12 after sub-solvus heat treatment.The dissolution of primaryγ'phase under super-solvus heat treatment leads to the growth of mean grain size up to ASTM 7.8.The inclusion fatigue origins at 650℃stress-controled tests and 700℃/0~0.8%strain controled tests of the super-solvus specimens are less than 15%,but more than 85%in the sub-solvus specimens.The fatigue origins of sub-solvus specimens are mainly small size inclusions,and the fatigue properties are not weaken.The fatigue origin type of the specimens under the control of 700℃with large strain(strain≥1.0%)is not decided by heat treatment process,the fatigue cracks only initiate on the surface and extremely sensitive to the inclusions nearby.
作者
尹超
熊江英
程俊义
王冲
郭建政
YIN Chao;XIONG Jiangying;CHENG Junyi;WANG Chong;GUO Jianzheng(Shenzhen Wedge Central South Research Institute Co.,Ltd.,Shenzhen 518035,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《粉末冶金工业》
北大核心
2024年第6期13-19,共7页
Powder Metallurgy Industry
基金
国家科技重大专项资助项目(2017-Ⅵ-0009-0080)
深圳市工业和信息化局项目(201806071114243770)
关键词
粉末高温合金
热处理
疲劳源类型
疲劳寿命
夹杂物
晶粒度
powder superalloy
heat treatment
type of fatigue source
fatigue life
inclusions
grain size
