Microstructure and Properties of Shielded Metal Arc Welding Welded Joints of 9Ni Steel
The microstructure and physical and chemical properties of 9Ni steel welded joints under manual arc welding process were inves-tigated for transport ships.The microstructure analysis showed that the weld seam of 9Ni steel under manual arc welding consists of austenite and precipitated phases,with a regular dendritic crystal morphology and obvious directionality.The structure of the welding heat affected zone is composed of Flat noodles martensite.The Flat noodles martensite structure in the welding coarse grain zone is evenly distributed,the segregation is dispersed,and the strength,toughness and mechanical properties are good.The chemical composition analysis shows that the chemical composition of the weld of the 9Ni steel plate matches well with the base metal.The physical and chemical properties of the welded joint indicate that the low-temperature toughness of the manual arc welding joint meets the standard requirements.Combined with theoreti-cal performance and fracture analysis,the low-temperature toughness of the manual arc welding joint is well-behaved.
NETL
NSTL
万方数据
维普
