Experimental study on large heat-input welding properties of 40 mm Q500MC steel plate
A study on large heat-input welding of 40 mm Q500MC steel plate was conducted using Mg-Ti compos-ite oxide metallurgical treatment to produce the 40 mm Q500MC steel plate,and a large heat-input welding experi-ment was conducted with a heat input of 276 KJ/cm.The results show that the mechanical properties of the steel plate meet the requirements of GB/T 1591,and the ductile brittle transition temperature(TVE)is lower than-60 ℃.The mechanical properties of the welded joint meet the standard requirements too,and the impact toughness at 0 ℃ and-20 ℃ in each position of the heat affected zone meets the standard requirements with a certain margin.Compared to the base material,the impact energy of the welding heat affected zone at 0 ℃ is reduced by about 56％,and the impact energy at-20℃is reduced by about 77％.The toughness to brittleness transition temper-ature(TVE)in the heat affected zone is about-18.4 ℃.After high heat-input welding,the coarse grain heat af-fected zone obtains a structure mainly composed of intragranular acicular ferrite,with an ideal toughness level.The width of the normalized zone in the heat affected zone can reach 5～6 mm,and the structure is mainly com-posed of ferrite and pearlite.The corresponding area has low hardness and severe softening.
万方数据
维普
