Ultra-thin precision stainless steel foil with high strength and high plasticity and production method thereof

Abstract

A method for producing a stainless steel foil comprises the following steps: rolling a raw material steel coil in an intermediate rolling process comprising three rolling processes; rolling the finished product in the rolling process; annealing and straightening the finished product. The application also provides a stainless steel foil prepared by the method. The method can solve the defect that the high strength and high plasticity of the ultra-thin stainless steel foil are difficult to meet at the same time.

1 . A method for producing a stainless steel foil, comprising the following steps of:
 rolling a raw material steel coil in an intermediate rolling process comprising three rolling processes;   finished product rolling process;   carrying out annealing treatment and straightening treatment on the finished product.   
     
     
         2 . The method for producing a stainless steel foil according to  claim 1 , wherein the raw material steel coil is 301 L steel coil. 
     
     
         3 . The method for producing a stainless steel foil according to  claim 1 , wherein the intermediate rolling process comprises a first rolling process with a deformation of 45%˜55%, a second rolling process with a deformation of 50%˜60%, and a third rolling process with a deformation of 50%˜60%, wherein high-temperature intermediate flexible bright annealing is respectively carried out immediately after the first rolling process, the second rolling process and the third rolling process are completed, with an annealing temperature being 950˜1150° C., and an annealing TV value being 2.5˜15, and TV values of the three annealing processes are gradually reduced. 
     
     
         4 . The method for producing a stainless steel foil according to  claim 3 , wherein each rolling process of the intermediate rolling process adopts five rolling passes, wherein, a high-roughness wire drawing roller is adopted in a first pass, the material of the roller is M2, the roughness Ra of the roller is 1.5˜3.0 μm, and a single pass deformation is 23%˜28%; rollers with a roughness Ra of 0.1˜0.5 μm are adopted for the remaining passes. 
     
     
         5 . The method for producing a stainless steel foil according to  claim 1 , wherein the finished product rolling process sequentially comprises: a first rolling pass with a deformation of 25%˜30%; a second rolling pass with deformation of 20%˜28%; a third rolling pass with deformation of 15%˜20%; a fourth rolling pass with a deformation of 5%˜10%; wherein, after finishing the third rolling pass, a TA stress relieving heat treatment is carried out at 600˜800° C. and a TV value is not less than 1, and then the fourth rolling pass is carried out. 
     
     
         6 . The method for producing a stainless steel foil according to  claim 1 , wherein the rolling tension is 230˜300 N/mm 2  and the rolling force is ≤500 KN in the finished product rolling process. 
     
     
         7 . The method for producing a stainless steel foil according to  claim 1 , wherein for a work roller used in the finished product rolling process, the diameter is φ20˜30 mm, the material is a molybdenum high speed steel, the roughness Ra is 0.1˜0.25 μm, and the surface hardness is HRC 63˜68. 
     
     
         8 . The method for producing a stainless steel foil according to  claim 1 , wherein the annealing temperature of the finished product is 900˜1100° C. 
     
     
         9 . The method for producing a stainless steel foil according to  claim 1 , wherein the straightening treatment adopts 23-rollers stretch-bend straightening, with an opening degree of −1.5˜−2.0 mm and an elongation of 0.3%˜0.45%, and the diameter of the straightening roller is 12˜16 mm. 
     
     
         10 . A stainless steel foil obtained by the method for producing a stainless steel foil according to  claim 1 , wherein the stainless steel foil has a thickness of ≤0.05 mm, a width of ≥600 mm, a tensile strength of ≥650 Mpa, and an elongation of ≥50%.