Effect of Mo Microalloying on High Temperature Mechanical Properties and Microstructure of 82B Steel
The influence of 82B steel with Mo(mass fraction)of 0.02%,0.04%,0.07%and 0.11%on microstruc-tures and properties after high temperature stretching at different temperatures and the toughness mechanism of Mo ele-ment on 82B high carbon steel were studied.The results showed that:(1)During 200-300 ℃ high temperatures ten-sile,four groups of experimental steels had good mechanical properties,at 300 ℃ to reach the peak,it was optimal ex-periment group with Mo content 0.11%,tensile strength increased from 1 139 MPa to 1 192 MPa,yield strength slightly reduced to 736 MPa,elongation and section shrinkage significantly increased to 22%and 72.9%.Compared to the experimental steels with 0.02%Mo content,the yield strength reduced by about 5%,but the tensile strength in-creased by 5%,the elongation and section shrinkage increased significantly,and the plasticity increased simultaneously with the Mo content,with the temperature continued to rise,the mechanical properties tended to decrease as the materi-als start to soften.(2)When the Mo content was 0.02%and 0.04%,the microstructures except carburite gradually in-creased with the increasing of tensile temperature,sorbite and pearlite did not appear obvious changes,and the same as room temperature,when the Mo content increased to 0.07%and 0.11%,sorbite and pearlite clusters are progressively finer and more evenly distributed.At the same time,four groups of experimental steels showed blue brittleness during high temperature tensile at 300 ℃,through the fractures observation found that there was Al,Si and other elements of in-clusions,and failure mode was ductile fracture,the fracture can mainly be divided into the shear lip areas and fiber ar-eas,the shear lip areas with the increase in temperature gradually reduced.
82B SteelMo MicroalloyingTensile StrengthHigh Temperature TensileRefractory Steel