高强GH4738合金成分设计计算与验证  

Composition Optimization Design and Verification for Nickel Based High Strength Superalloy GH4738

作　　者：姚志浩[1] 董建新[1] 张麦仓[1] 张玉峰 谢伟[3] 李蓬川[4] 

机构地区：[1]北京科技大学,北京100083 [2]中国石油集团渤海石油装备制造有限公司,天津300457 [3]宝钢特殊钢分公司,上海200940 [4]中国第二重型机械集团公司,四川德阳608013

出　　处：《稀有金属材料与工程》2017年第11期3382-3387,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51401020);教育部博士学科点新教师专项科研基金(20130006120005);北京市基金(2154051);国家留学基金委资助

摘　　要：高强GH4738高温合金是超大功率烟气轮机/燃气轮机涡轮盘的候选材料,利用Thermo-Calc及JMat Pro软件进行成分设计优化及抗拉强度预测进而实验验证。研究了不同C,Al,Ti及Cr等元素对该合金中相析出规律及其合金力学性能的变化规律;基于计算结果,制备了不同Al,Ti含量的GH4738合金,测试了其室温抗拉强度并对确定的超大型盘件用高强GH4738合金成分进行相分析研究。结果显示,C含量的增加,可促进碳化物M_(23)C_6及MC析出量的增加及其回溶温度的提高,但其对γ?相含量的变化几乎无影响;Al,Ti含量的增加,都可明显提高合金γ?相回溶温度及其析出量,并有利于合金抗拉强度的提高;Cr含量的增加,可提高γ?相的回溶温度,但对其析出量影响不大;影响合金中γ?相回溶温度及析出量的合金元素顺序依次为Al,Ti,Cr;高强GH4738合金成分设计原则为适当降低C含量,提高Al,Ti含量至合金成分范围高限;高强GH4738合金中γ?相占约24.0%,其点阵常数为a_0=0.357~0.359 nm,其组成结构为:(Ni_(0.9236)Co_(0.0415)Fe_(0.0025)Cr_(0.0322))_3(Cr_(0.0972)Al_(0.3585)Ti_(0.5059)Mo_(0.0366)Co_(0.0018))。该研究结果为中国大尺寸GH4738难变形高温合金涡轮盘提供了的成分设计思路。High strength GH4738 superalloy is a candidate for oversized turbine disc in gas turbine field.Thermo-Calc and JMat Pro software were used to optimize composition of the alloy combined with experiments.The effects of elements C,Al,Ti and Cr on phase precipitation and mechanical properties were calculated.Based on the calculated results,GH4738 superalloys with different contents of Al and Ti were fabricated,and tensile strength properties at room temperature were examined.The final elements of high strength GH4738superalloy were determined and their phases were analyzed.The results show that increasing of C content can promote an increase in carbides（M_（23）C_6 and MC）amount and solution temperature,but it almost has no effect on theγ？phase amount.Elements Al,Ti can significantly increase solution temperature and its amount forγ？phase and improve strength of GH4738 alloy.Solution temperature ofγ？phase increases with increasing of element Cr,but it hardly changes precipitating ofγ？phase.The incidence order of elements on solution temperature andγ？phase amounts is AlTiCr.The design principle of GH4738 superalloy is to reduce the C content,and improve Al,Ti content to the upper limit in the range of the alloy.The amount ofγ？phase in GH4738 super alloy is about 24.0%,its lattice constanta_0=0.357~0.359 nm,and its composition is（Ni_（0.9236）Co_（0.0415）Fe_（0.0025）Cr_（0.0322））_3（Cr_（0.0972）Al_（0.3585）Ti_（0.5059）Mo_（0.0366）Co_（0.0018））.The results provide adesign idea for large sized high strength GH4738 superalloy turbine disk.

关 键 词：高强GH4738合金 涡轮盘 合金设计 力学性能 相分析 

分 类 号：TG132.3[一般工业技术—材料科学与工程]