Fe-ni or fe-ni-co or fe-ni-co-cu alloy strip with improved cuttability

Abstract

Strip made of an austenitic Fe—Ni alloy or Fe—Ni—Co alloy or Fe—Ni—Co—Cu alloy, the chemical composition of the alloy of which comprises, in % by weight: 30%≦Ni≦70%; 0%≦Cu+2×Co≦20%; 0%≦Mn+Cr<5%; 0%≦W+2×Mo≦2%; 0%≦Ti+V+Nb+Al≦1%; 0.0005%≦B≦0.007%; the balance being iron and impurities such as C, S, P, O and N; the chemical composition being such that Fe+Ni+Cu+Co≧95%. The alloy has a cubic texture with a cubic texture index D c ≧7. Process for manufacturing a strip. Process for manufacturing a part by mechanical cutting.

1 . Strip made of an austenitic Fe—Ni alloy or Fe—Ni—Co alloy or Fe—Ni—Co—Cu alloy, characterized in that the chemical composition of the alloy comprises, in % by weight:  
       30%≦Ni≦70% 0%≦Cu+2×Co≦20% 0%≦Mn+Cr<5% 0%≦W+2×Mo≦2% 0%≦Ti+V+Nb+Al≦1% 0.0005%≦B≦0.007%  
       the balance being iron and impurities such as C, S, P, O and N; the chemical composition being such that Fe+Ni+Cu+Co≧95%,  
       and in that the alloy has a cubic texture with a cubic texture index D c ≧7.  
     
     
         2 . Strip according to  claim 1 , characterized in that:  
       0.0007%≦B≦0.004%.  
     
     
         3 . Strip according to  claim 1  or  claim 2 , characterized in that D c >10.  
     
     
         4 . Strip according to any one of  claims 1  to  3 , characterized in that the carbon content of the alloy is less than or equal to 0.05%.  
     
     
         5 . Strip according to any one of  claims 1  to  4 , characterized in that the sulphur content of the alloy is less than or equal to 0.01%.  
     
     
         6 . Strip according to  claim 5 , characterized in that the sulphur content of the alloy is less than or equal to 0.007%.  
     
     
         7 . Strip according to any one of  claims 1  to  6 , characterized in that the oxygen content is less than 0.005%.  
     
     
         8 . Process for manufacturing a strip according to any one of  claims 1  to  7 , characterized in that: 
 a strip made of an alloy whose composition is defined by  claims 1  to  7  is manufactured by cold-rolling with a deformation ratio of greater than 80%;  
 a fine-grain recrystallization annealing operation is carried out on the strip;  
 and, optionally, a complementary cold-rolling operation is carried out with a deformation ratio of less than 40%.  
 
     
     
         9 . Process for manufacturing a part by mechanical cutting or by mechanical cutting and drawing, characterized in that: 
 a blank is taken from a strip according to any one of  claims 1  to  7 ;    and at least one mechanical cutting operation and optionally at least one drawing operation are carried out on the blank, it being possible for the at least one drawing operation to be carried out before or after the at least one mechanical cutting operation.    
     
     
         10 . Process according to  claim 9 , characterized in that the part is an electron-gun part with a hole through which the electrons pass, or in that the part is a leadframe with connection leads, or in that the part is a magnetic core of a micromotor or transformer.