(蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 采用SEM、OM及XRD和壓縮試驗(yàn)等手段，研究GH3625合金管材在冷塑性變形和退火熱處理過程中位錯(cuò)密度和硬度的變化規(guī)律，探討合金中孿晶的形態(tài)及其形成機(jī)制。結(jié)果表明：冷變形量是影響GH3625合金管材塑性變形機(jī)制的主要因素，ε＜0.05時(shí)，塑性變形以滑移變形為主，其主要硬化機(jī)制是位錯(cuò)強(qiáng)化；隨著冷變形量的增加，合金的位錯(cuò)密度和硬度顯著增加，組織中產(chǎn)生大量的形變孿晶，塑性變形方式由滑移主導(dǎo)的變形轉(zhuǎn)變?yōu)橐詫\生為主導(dǎo)的變形，其主要的硬化機(jī)制是孿晶強(qiáng)化；隨著退火溫度的增加，GH3625合金管材的位錯(cuò)密度和硬度逐漸降低，退火孿晶的形態(tài)從中止型逐漸轉(zhuǎn)變?yōu)榇┚汀H3625合金管材在冷變形和退火過程中出現(xiàn)不同形態(tài)的孿晶，可分為中止型孿晶和穿晶型孿晶，前者的形成機(jī)理是不全位錯(cuò)按極軸運(yùn)動(dòng)的結(jié)果，后者形成的本質(zhì)是層錯(cuò)。
關(guān)鍵字: GH3625合金；加工硬化；退火軟化；形變孿晶；退火孿晶
（State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The evolution of dislocation density, hardness and microstructure of GH3625 superalloy tube during cold plastic deformation and annealing heat treatment were investigated by SEM, OM, XRD and compression test. And the morphology and formation mechanism of twin in the alloy were discussed. The results show that the cold deformation is the main factor which affects the plastic deformation mechanism of GH3625 superalloy. When true strain is less than 0.05, the plastic deformation is dominated by slip deformation, and the mechanism of work hardening is dislocation strengthening. With the increase of the cold deformation, dislocation density and hardness of GH3625 superalloy tube significant increase as well as a large amount of deformation twins appear in the microstructure, and the deformation mode changes from slip-dominated deformation to twin-dominated deformation, and the mechanism is twin strengthening. With the increase of annealing temperature, dislocation density and hardness of GH3625 superalloy tube gradually decrease, and the morphology of annealing twin changes gradually from suspended to transgranular. GH3625 superalloy tube in cold deformarion and annealing processs appears different morphologies of twin, it can be divided into suspended twin and transgranular twin which have different formation mechanisms in growth, the former is the motion of partial dislocations, the latter is the stacking faults mechanism.
Key words: GH3625 superalloy; work hardening; annealing softening; deformation twin; annealing twin
