高级检索
郭枭, 徐锴, 魏超, 韩莹, 吕晓春. GH2132高温合金熔敷金属结晶裂纹敏感性[J]. 焊接学报, 2022, 43(11): 30-35, 125. DOI: 10.12073/j.hjxb.20220623002
引用本文: 郭枭, 徐锴, 魏超, 韩莹, 吕晓春. GH2132高温合金熔敷金属结晶裂纹敏感性[J]. 焊接学报, 2022, 43(11): 30-35, 125. DOI: 10.12073/j.hjxb.20220623002
GUO Xiao, XU Kai, WEI Chao, HAN Ying, LV Xiaochun. Solidification crack sensitivity of GH2132 superalloy deposited metal[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2022, 43(11): 30-35, 125. DOI: 10.12073/j.hjxb.20220623002
Citation: GUO Xiao, XU Kai, WEI Chao, HAN Ying, LV Xiaochun. Solidification crack sensitivity of GH2132 superalloy deposited metal[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2022, 43(11): 30-35, 125. DOI: 10.12073/j.hjxb.20220623002

GH2132高温合金熔敷金属结晶裂纹敏感性

Solidification crack sensitivity of GH2132 superalloy deposited metal

  • 摘要: 针对GH2132高温合金熔敷金属热裂纹敏感性问题,通过采用试制焊丝、熔敷金属焊接试验、组织及断口分析、凝固计算等手段对熔敷金属组织、凝固行为、开裂机制等进行了研究. 结果表明,试验熔敷金属金相组织主要由柱状树枝晶γ相(NiCrFe固溶体)、枝晶间富Ti的Laves相(Cr,Fe,Ni)2 (Ti,Mo)、MC碳化物与共晶组织组成,凝固路径为L→L + γ→L + γ + MC→L + γ + MC + Laves→γ + MC + Laves,裂纹断口呈典型的鹅卵石共晶花样,整个断口形貌被呈自由表面的液膜所覆盖,属于发生在高温段的结晶裂纹. 结晶裂纹开裂机理为在凝固过程的终了阶段,发生了L→γ + Laves的低熔点共晶反应,在凝固收缩应力作用下,残余液相未及时补充而形成. Laves相的形成主要与凝固过程中Ti元素的偏析有关,理论计算结果表明,GH2132结晶裂纹指数(solidification cracking index, SCI)值为1944 ℃,(solidification temperature range, STR)为258 ℃,在结晶裂纹敏感性评价方面,相比STRSCI指标能相对更为合理地实现结晶裂纹敏感性的量化评价,但仍存在考虑因素不全等问题.

     

    Abstract: Aiming at the problem of high sensitivity of hot crack in GH2132 superalloy welding, the microstructure, solidification behavior and cracking mechanism of GTAW deposited metal were studied by new developed welding wire, welding test of deposited metal, microstructural and fracture analysis, solidification calculation. The results show that the microstructure of the deposited metal was mainly composed of columnar dendrite γ phase (NiCrFe solid solution), Ti rich in Laves phase (Cr, Fe, Ni)2(Ti, Mo), MC carbides and eutectic structure in the interdendritic. The solidification mode of the new developing wire was L→L + γ→L + γ + MC→L + γ + MC + Laves→γ + MC + Laves. The fracture surface showed typical cobblestone eutectic pattern, and the whole fracture morphology was covered by liquid film with free surface, indicating that the crystal crack occurred in the high temperature section. The mechanism of solidification crack was L→γ + Laves eutectic reaction with low melting point occurs at the terminal stage of solidification process. Under the action of solidification shrinkage stress, the residual liquid phase was not replenished in time and formed. The formation of Laves phase was mainly related to the segregation of Ti element during solidification. The theoretical calculation results show that the SCI (Solidification Cracking Index) value of GH2132 was 1944 ℃, and the STR (Solidification Cracking Range) was 258 ℃. In the evaluation of crystal crack sensitivity, SCI index can achieve the quantitative evaluation of crystal crack sensitivity more reasonably than STR, but there are still some problems such as incomplete factors to be considered.

     

/

返回文章
返回