35CrMo齿轮堆焊接头组织与力学性能分析

Analysis of Microstructures and Mechanical Properties of 35CrMo Gear Overlaying Joint

采用CO_2气体保护焊的方式进行35CrMo齿轮的堆焊并对接头处进行组织分析和力学性能分析。结果表明,采用NER70S-6焊丝作为填充焊丝能够获得良好的焊接接头,在焊缝界面处会生成与熔合区晶粒联结长大的柱状晶,并且在距离焊缝较远处产生了侧板条铁素体、针状铁素体和魏氏组织。在热影响区的正火区通过两次重结晶作用产生了细小的珠光体和铁素体组织。堆焊接头焊缝区的显微硬度最高可达HV220,热影响区显微硬度在HV200左右。

Through making use of CO2 gas shielding,both microstructure observation and mechanics property analysis of 35CrMo gear＇s overlaying and joints were implemented to show that,taking NER70S-6 as filling wire can bring about good welding joint;and on the weld interface,the columnar crystal grows up between the welding seam area and fusion zone,and at the position far from the welding seam,a side-plate ferrite,acicular ferrite and Widmannstatten structure can appear;and in normalized zone of the heat affected area,the two times of recrystallization generate tiny pearlite and ferritic structure.The microhardness in the seam area of welding joint can reach HV220 at most and the micro hardness in the heat affected zone stays at about HV200.