Microstructures and Mechanical Properties of theMn-N Alloyed Lean Duplex Stainless Steel Processed b

• 作 者: ZhaoYan;LiuZhenyu;WangGuodong;
• 机 构: The State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang Liaoning,China
• 出 处: 第十届中国钢铁年会暨第六届宝钢学术年会
• 发表日期: 2015年期

　　Lean duplex stainless steel,in which nickel is replaced by manganese and nitrogen,is one of the most important trends for developing high strength stainless steels.However,manufacturing thin gage strips of lean duplex stainless steelhas been one of the most challenging technologies in the production of stainless steels.In the present work,lean duplex stainless steel with the composition of Fe-18.7Cr-6.3Mn-0.38N was fabricated by twin-roll strip casting,in which serious pore defects can be effectively avoided as compared to conventional ingot casting.The solidification structure observed by OMindicates that no solidified dendrites have beenformedthrough surface to center of the cast strip,and the coarse equi-axedgrainswere formed in the center.The cast strip was hot rolled and cold rolled to the final thickness of 0.5mm,with no obvious edge cracks having been formed during both hot and cold rolling.After the annealing treatment at 1050°C for 5min following the cold rolling,distribution of Mn and Cr in the cast strip can be further homogenized.The cold rolled and annealed cast strip exhibited an excellent combinationof strength and ductility,with the ultimate tensile strength and elongation having been measured to be 1000MPa and 65%,respectively.TEM micrographs clearly showed that strain induced martensitic transformation had occurred during plastic deformation.