Numerical Simulation Of Quenching Process Of High Strength Steel Shee And Distortion Control

High strength sheet is main applied to make bulletproof components.Excellent bulletproof performance can be brought into play only after quenching and high tempering though this kind of steel is different from other steels.In the process of heating and quenching,distortion would occur.Distortion would reach 500mm after quenching without any restrict;in the following flattening procedure,it will consume too much energy or crack would occur in the process of flattening for strength and hardness of the steel will improve after quenching.To ensure high strength and small distortion after quenching,analysis of quenching should be made and effectual measure of distortion control should be given.Investigation and discuss of this subject is made in this paper.For temperature,stress and structure testing on line is impossible currently for technique limits,so it is necessary to recur to computer simulation technology to study main physical parameter of quenching,which can provide academic assistance to yielding technology improvements and mould design.For the thickness of the plate is so small to its breadth and length,which can be considered as a two dimensional infinite plate,so a planar mould of ANSYS could be put into use to simulate the quenching process.A thermal-structural coupled simulation can show how temperature and remain stress distributes,and distortion can be calculated,pressure to flatten plate displayed according to deflection theory.Study and analysis in this paper indicate that:1.TTT curve and dynamic transformation equation could be put into use in temperature?stress and strain distribution,transformation calculation;2.Temperature of the sheet center can be cooling down to Ms in 5 seconds,hardness test indicates that the texture is entire martensite;3.Calculation indicates that after the proocess of quenching with press,the flatness of armor board can be restricted to 2?3mm/m2,4.If the time of roller transmitting can be controlled appropriately,non-martensite transfornmation would take place before water spray quenching.The innovation of this paper embodies such aspects:1.All physical properties variable to temperature are put into consideration,and non-linear calculation is adopted to show iemperature and stress distribution field.2.A special mould was designed acccording to peculiar shape of the armor sheet,it can satisfy industrial yield after technical experiment.