摘要
采用热丝脉冲非熔化极惰性气体保护焊(TIG)在低电流(峰值/基值电流为160 A/95 A)和不同焊接速度(220~300 mm·min^(−1))下于AISI 4130钢表面制备Inconel 625合金堆焊层,研究了焊接电流与焊接速度对堆焊层成形性能及显微组织的影响,并与高电流(峰值/基值电流为190 A/110 A)条件下进行对比。结果表明:随着焊接速度的增加,低电流下堆焊层的宽度和熔深降低,高度以及熔深与高度之比先降后升;低电流下堆焊层的宽度、熔深及熔深与高度之比低于高电流下,高度则高于高电流下。低电流、低焊接速度可获得窄且高,稀释率低的堆焊层。低电流下堆焊层截面近表面和远离熔池底部主要形成胞状晶、胞状树枝晶,熔池底部以平面晶为主;随着焊接速度的降低,平面晶区扩大,近表面晶粒向柱状晶或胞状树枝晶发展,远离熔池底部的晶粒向胞状晶发展。在峰值/基值电流160 A/95 A、焊接速度240 mm·min^(−1)和搭接率30%条件下制备的3层10道堆焊层连续致密,显微硬度在(280±20)HV,堆焊后还需进行退火处理以降低硬度。
Inconel 625 alloy cladding layer was prepared on AISI 4130 steel surface by hot-wire tungsten inert gas(TIG)welding under a low current(peak/base currents of 160 A/95 A)and different welding speeds(220‒300 mm·min^(−1)).The effects of welding current and welding speed on the formability and microstructure of the cladding layer were investigated,and compared with those at a high current(peak/base currents of 190 A/110 A).The results show that at the low current,with the increase of welding speed,the width,depth of fusion of the cladding layer decreased,and the height and the ratio of depth of fusion to height of the cladding layer first decreased and then increased.The width,depth of fusion and the ratio of depth of fusion to height of the cladding layer at the low current were lower than those at the high current,and the height was higher than that at a high current.Low current and low welding speed could obtain the narrow and high cladding layer with low dilution rate.At the low current,cellular crystals and dendritic crystals were mainly formed near the surface and away from the bottom of the molten pool on the cross-section of the cladding layer,and planar crystals were dominant at the bottom of the molten pool.With the decrease of welding speed,the planar crystal region expanded,the grains near the surface developed into columnar or dendritic crystals,and the grains away from the bottom of the molten pool developed into cellular crystals.Under 160 A/95 A peak/base current,240 mm·min^(−1) welding speed and 30%bonding rate,the three-layer ten-pass cladding layer was continuously dense and the microhardness was(280±20)HV.After cladding welding,annealing treatment was required to reduce the hardness.
作者
蔡军
陈成
CAI Jun;CHEN Cheng(School of Mechanical and Electrical Engineering,Nantong Open University,Nantong 226006,China;School of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211816,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第11期61-68,共8页
Materials For Mechanical Engineering
基金
南通开放大学重大课题(2024ZDA01)。
作者简介
蔡军(1987-),男,江苏南通人,讲师,硕士。
