In　order　to　improve　the　quality　of　electromagnetic　riveting　joints,TB2　rivets　at　20　℃　and　heated　to　100,200　and　300　℃　were　tested　for　electromagnetic　riveting　technology　under　210　V　discharge　voltage.　The　rivet　heads　were　observed　by　optical　microscope　(OM),scanning　electron　microscope(SEM)and　scanning　transmission　electron　microscope(STEM),the　effects　of　different　initial　temperatures　on　riveting　effects　were　discussed,and　the　microstructure　evolution　in　adiabatic　shear　band(ASB)and　the　formation　mechanism　of　the　shear　band　were　analyzed.　The　results　showed　that　with　the　increase　of　initial　temperature,the　material　was　softened　by　heating,the　maximum　deformation　of　TB2　gradually　increased,and　the　plasticity　becomes　better,which　was　helpful　for　rivet　forming.　At　20　℃,the　maximum　deformation　was　38%,when　the　deformation　reached　40%,the　specimen　shears　along　45°　direction.　When　the　temperature　reached　200　℃,the　maximum　deformation　of　TB2　samples　was　52%,which　increased　by　8%.　When　the　temperature　reached　300　℃,the　maximum　deformation　of　TB2　sample　was　close　to　58%,and　the　maximum　deformation　was　increased　by　20%.　Through　SEM　observation　on　TB2　rivet　upsets　with　different　deformation,it　was　found　that　ASB　would　initially　appear　around　the　rivet　upsets,and　the　width　of　ASB　would　decrease　with　the　increase　of　deformation　within　a　certain　amount　of　deformation.　During　the　whole　adiabatic　shear　deformation　process,ASB　had　experienced　three　stages　of　initiation　and　extension　to　fracture,which　was　a　shear　band　from　the　formation　of　the　main　shear　band　to　the　formation　of　both　the　primary　and　secondary　shear　bands,and　then　to　the　final　fracture.　With　the　increase　of　the　initial　temperature,ASB　would　be　delayed.　ASB　width　ranged　from　20　to　50　μm　at　different　temperatures　and　deformations.　With　the　increase　of　deformation,the　width　of　ASB　at　20,100　and　200　℃　showed　a　downward　trend.　The　adiabatic　shear　band　would　be　roughly　formed　at　30%　of　the　deformation,but　when　the　temperature　rose　to　300　℃,30%　of　the　deformation　was　not　enough　to　occur,and　it　could　be　formed　only　when　it　reached　about　40%.　For　the　shear　band　width　at　300　℃,it　showed　a　trend　of　decreasing　first　and　then　increasing,mainly　because　the　deformation　played　a　leading　role　in　the　formation　of　the　shear　band　at　the　beginning　of　the　deformation　of　the　header,and　the　width　of　the　shear　band　decreased　with　the　increase　of　the　deformation.　When　the　deformation　reached　a　certain　stage,the　temperature　of　the　header　rose　rapidly　due　to　the　adiabatic　effect.　At　this　time,the　temperature　played　a　leading　role　in　the　influence　on　the　width　of　the　shear　band.　The　rise　of　temperature　led　to　more　uniform　deformation　of　the　header,instability　of　materials　in　more　areas,and　finally　the　adiabatic　shear　band.　When　the　deformation　continued　to　increase,the　shear　area　would　be　more　concentrated.　The　width　of　the　shear　band　might　decrease　when　it　rose　to　a　certain　value.　When　the　deformation　reached　a　certain　stage,the　header　would　break.　Focused　ion　beam(FIB)was　used　to　cut　the　inner　and　outer　edges　of　the　shear　band　of　TB2.　TB2　samples　with　40%　deformation　at　20　and　300　℃　were　taken　for　STEM,and　it　was　found　that　the　dislocation　density　in　the　direction　formed　the　transition　zone　to　the　center　of　ASB　decreased　gradually,and　dislocation　cells　existed　in　the　elongated　large　grains.　With　the　increase　of　deformation,the　large　grains　were　gradually　broken　into　equiaxed　nano　grains,consistent　with　the　characteristics　of　rotational　recrystallized　grain　formation.　©　2024　Editorial　Office　of　Chinese　Journal　of　Rare　Metals.　All　rights　reserved.