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本文研究了温度,应力对定向凝固镍基高温合金的第一阶段蠕变量的影响.大多数镍基合金经定向凝固后,在中温(700—800℃)、高应力(490—784MN/m~2)下纵向的第一阶段蠕变量比普通铸造合金显著增大,这是由位错切过γ′粒子的蠕变机制所决定.定向凝固DZ-3合金的中温纵向蠕变量相当低,与普通铸造CCK3合金相同.这是由位错攀移越过γ粒子的蠕变机制所决定.所有定向凝固合金横向的第一阶段蠕变量与相应的普通铸造合金相同.γ/γ′点阵错配度愈大,强度水平愈高,定向凝固合金的纵向第一阶段蠕变量愈低.在高温(850—980℃)、低应力(196—343MN/m~2)下,定向凝固镍基高温合金的第一阶段蠕变量与普通铸造合金相当.高温下,所有合金第一阶段蠕变量也随蠕变应力提高而略有增加.
In this paper, the effects of temperature and stress on the creep of the first stage of directional solidification Ni-based superalloy were studied.Most nickel-based alloys after the directional solidification at medium temperature (700-800 ℃), high stress (490-784MN / m ~ 2), the creep of the first stage in the lower longitudinal direction is significantly larger than that of ordinary cast alloy, which is determined by the creep mechanism of dislocation-cut γ ’particles.The longitudinal creep of the DZ- Low, as with the conventional cast CCK3 alloy, which is determined by the creep mechanism of the dislocation climb across the gamma particles.The first stage creep of all the directional solidified alloy is the same as the corresponding normal cast alloy, γ / γ ’ The higher the lattice mismatch, the higher the strength is, the lower the creep of the first phase of the directional solidified alloy is. At high temperature (850-980 ℃) and low stress (196-343MN / m ~ 2) The first-stage creep of the solidified nickel-base superalloy corresponds to that of the normal cast alloy, and the creep of the first stage of all the alloys also increases slightly with creep stress at high temperature.