Research on High-Temperature Damage Behavior of Super Martensitic Stainless Steel 04Cr13Ni5Mo Based on Finite Element Simulation

04Cr13Ni5Mo martensitic stainless steel is extremely sensitive to forging temperature and is prone to generating extremely large cracks, which leads to the failure of forging. Therefore, high-temperature tensile tests were performed on 04Cr13Ni5Mo martensitic stainless steel using a Gleeble-1500D thermo-mechanical simulator to investigate its damage mechanisms. The tests covered a temperature range of 950-1200 °C and strain rates of 0.001-1 s^-1. The high-temperature damage behavior and tissue evolution law at high temperatures were studied by means of EBSD, TEM, etc. Secondly, two high-temperature damage models of 04Cr13Ni5Mo, namely Normalized Cockcroft and Latham (NCL) and Oyane, were established by combining optimization algorithm and finite element simulation. Then, the two high-temperature damage models were integrated into the Forge^®NxT 3.2 finite element software. Simulated thermal tensile tests were conducted on 04Cr13Ni5Mo at temperatures from 950 to 1200 °C, strain rates from 0.001 to 1 s^-1. A comparison was made between the predicted and experimentally measured fracture displacements of the tensile specimens. The calculated correlation coefficients (<i>R</i>) were 0.995 and 0.991, respectively. It was determined that the NCL model has better simulation accuracy for predicting the forging cracks of 04Cr13Ni5Mo. The reliability of the finite element method for predicting forging crack defects in 04Cr13Ni5Mo forgings was established.