Effect Of Cold Rolling And Low Temperature Short Time Aging On Microstructure Evolution And Mechanical Properties Of 2101 Duplex Stainless Steel

With the development of the times and the exploitation of non-renewable resources,sustainable development has become a hot spot that today's society has to pay attention to.Traditional duplex stainless steel contains high content of Ni and other expensive alloy components.Therefore,the development of resource-saving Mn-Ngeneration Ni duplex stainless steel to replace traditional duplex stainless steel has become a research hotspot.It has been widely used in anti-corrosion,automotive industry and Construction industry.This article takes economical 2101 duplex stainless steel as the research object,and explores the influence of cold rolling deformation and low temperature short-aging on the mechanical properties and microstructure of 2101 duplex stainless steel.Using SEM,TEM,EBSD,XRD,hardness and mechanical properties testing and other methods to characterize the microstructure and mechanical properties of 2101 duplex stainless steel,and then reveal the internal relationship among cold rolling deformation,low temperature short time aging,mechanical properties and microstructure.The solid solution 2101 duplex stainless steel was subjected to cold rolling deformation with different deformation amounts of 40?80%.After cold rolling,the austenite and ferrite in the steel are further elongated along the rolling direction to form a strip-like structure.As the amount of deformation increases,it evolves into a lamellar structure,in which deformation twins appear in the austenite and a martensite transformation occurs.The content of deformation-induced martensite increases as the amount of deformation increases.After being deformed by cold rolling,the strength of the steel has been significantly improved and the elongation has been drastically reduced.When the deformation is 80%,the tensile strength reaches 1460.36 MPa,the yield strength reached 1352.80 MPa,and the elongation reaches 10.17%.The 2101 duplex stainless steel formed by different cold rolling deformations was subjected to low temperature short-age treatment at 550?+5 min.The results show that after the aging treatment,the reverse transformation process of deformed martensite to austenite occurred in the cold-rolled steel,and nano-scale austenite grains were formed.At the same time,the ferrite recovered,and the strength of the material was improved.Maintained and improved plasticity.After 60% reduction and short-term aging at low temperature,the tensile strength reached 1,450.85 MPa,the yield strength reached1378.70 MPa,the elongation reached 11.89%,and the cold-rolled 2101 duplex stainless steel with 60% deformation.In comparison,the tensile strength increased by 8.83%,the yield strength increased by 20.3%,and the elongation increased by 34.6%.The effect of aging time on the structure and properties of cold rolled 2101 duplex stainless steel was studied.As the aging time increases,the reversal variable of deformed martensite increases,and the number of defects such as internal dislocations in ferrite grains decreases with the increase of aging time,and the softening effect is obvious.As a result,the strength of steel decreases slightly with the increase of aging time,but the effect of elongation is not obvious,and the uniform elongation is improved.After aging at 550 ? for 30 min,the tensile strength,yield strength and elongation of 2101 duplex stainless steel with 60% cold rolling deformation reached to 1371.67 MPa,1280.16 MPa and 11.45%,respectively.The purpose of increasing plasticity properly while ensuring high strength has been achieved.