Study On F460Z Submerged Arc Welding Materials And Process For Marine Engineering

In this paper, according to the composition characteristics and application requirementof F460Z steel, on the basis of analyzing the characteristics of domestic and foreign relatedwire components, designed three different components SAW wire, made analysis of thecomposition, mechanical properties and diffusion of hydrogen in deposited metal.According to the result, used the first wire with CHF102flux did SAW F460Z joints tests indifferent welding procedure, researched the effects of welding heat input and interpasstemperature on properties and structure of F460Z SAW joints.Deposited metal test results show that: the first wire has the best comprehensiveproperties, the weld metal yield strength and tensile strength are495MPa and575MPa, theimpact energy in-60℃is140.2J, the content of diffusible hydrogen of2.655ml/100g.With the welding heat input is increased, the tensile strength of F460Z steel SAW jointsreduced; When the interpass temperature is150℃, the impact toughness reduced with theincreased of welding heat input; When the interpass temperature is200℃, the impacttoughness increased then reduced with the increased of welding heat input. With theinterpass temperature increased from150℃to200℃, the impact toughness increased butthe tensile strength reduced. In the range of this paper test, the best welding procedure ofF460Z SAW is30kJ/cm welding heat input and200℃interpass temperature.Welding in theprocess conditions, the tensile strength is581MPa, and the-60℃impact energy of weldseam、fusion line and fusion line2mm were130J,209J,210J.The SAW joint of F460Z steel weld seam zone is the columnar structure, white PFseparated out along the original austenite grain boundary, grain inside is small AF structure;HAZ overheated zone structure is bulk PF spread like nets; HAZ normalized zone structureis small ferrite spread with small carbonization. With the welding heat input increased, thewide of columnar structure in weld seam zone increased, the amount of the PF increased,the amount of AF reduced. With the interpass temperature increased from150℃to200℃,The columnar zone of weld zone column ratio gradually reduced, recrystallization zoneproportion increased.In the process of50kJ/cm welding heat input and interpass temperature of200℃, theF460Z steel SAW welded joints have eligible performance, conformed to CCS《materials and welding of the2012》 requirements, so, F460Z steel fit large welding heat input,propitious to improve welding productivity.