Research On The Forming Property Of Docol1200M Ultra High Strength Steel With Warm Drawing And Bulging

Automobile high strength steel has low plasticity，rebound resilience and othershortcomings such as serious oxidation in cold forming, so the surface quality is difficult tocontrol in hot forming and there are also other problems. In this paper, with the help of thesuccessful experience of the Warm Forging proposed temperature stamping method tosolve the problems of high strength steel forming,opening a new approaches for forming ofhigh strength steel.This paper has taken Docol1200M ultra high strength steel as the research object,studied the warm drawing and bulging formability of Docol1200M ultra-high strengthsteel.Firstly,the material mechanical properties at room temperature,100℃,200℃,300℃,400℃and500℃weregained by tensile test.According to the national standardsof experimental design, a Docol1200M ultra high strength steel drawing dies and a pull-bulging compound forming die at test temperature were manufactured.Then, throughsoftware simulation and the physical experiment measured Docol1200M ultra-highstrength steel expansion drawing performance and forming limit (FLD)diagram attemperature in the experiment.and measuring the intensity value after the forming of thematerial in each test temperature and hardness values, get the effect of temperature on thestrength and hardness of the material.Finally, through the observation on the fracturemorphology and microstructure, studied the warm drawing and bulging law ofDocol1200M ultra high strength steel plate.and summed up the most suitable temperaturepull inflation molding temperature of Docol1200M ultra high strength steel.The study indicates that drawing and bulging performance of Docol1200M ultra highstrength steel plate overall material increase with the rise of temperature, but at200℃and300℃, stretching forming properties of materials suddenly decreasedas the first kind oftemper brittleness and blue brittle phenomenon; Docol1200M super-high strength steelplate in unidirectional stress and stress, temperature change regularity of different effectson the forming limit,single way force the materials is not sensitive to the first kind oftemper brittleness; Before400℃, strength changed little material, to500℃, the strengthof material deformation from1400Mpa plunged to less than800Mpa at room temperature.The hardness value reached the highest at300℃; Considering obtained of Docol1200Multrahigh strength steel and most suitable temperature pull inflation molding temperature isabout400°C. According to the study, the most optimal forming temperature of super-strength steelDocol1200M has been found, the result shows that it is appropriate for super-strength steelto be formed by warm stamping technology, which lay the foundation for the warmforming of super-strength steel, and guide the future engineering applications in the field offorming super-strength steel.