scholarly journals Composition and orientation effects on the final recrystallization texture of coarse-grained Nb-containing AISI 430 ferritic stainless steels

2011 ◽  
Vol 528 (9) ◽  
pp. 3513-3519 ◽  
Author(s):  
R.P. Siqueira ◽  
H.R.Z. Sandim ◽  
T.R. Oliveira ◽  
D. Raabe
CORROSION ◽  
1986 ◽  
Vol 42 (2) ◽  
pp. 106-110 ◽  
Author(s):  
J. B. Lee

Abstract An electrochemical potentiokinetic reactivation (EPR) test has been developed for quantifying the degree of sensitization of ferritic stainless steels (SSs). This test is applicable to AISI 430, 430 Ti, 430 Nb, 434, 444, and 446. The test is conducted at 30 C in a deaerated 3 to 5 N H2SO4 solution. A test specimen is first passivated at + 400 mVSCE for 2 to 10 min, depending on the grade of SS, and then subjected to a reactivation step where the potential is decreased at a rate of 100 to 250 mV/min toward the open circuit potential (OCP) to determine whether a reactivation peak occurs. Results of the EPR test agree well with those of the Cu-CuSO4-50% H2SO4 immersion test.


2010 ◽  
Vol 638-642 ◽  
pp. 3009-3014 ◽  
Author(s):  
Rodrigo P. Siqueira ◽  
Hugo Ricardo Zschommler Sandim ◽  
Tarcisio R. Oliveira

Ferritic stainless steels (FSSs) have excellent corrosion resistance and good mechanical properties. Applications include heaters, houseware, and automotive exhaust systems. Alloying, even in small amounts, affects the recrystallization behavior of FSSs by selective dragging or pinning effects. In the present study, we present the main results regarding the recrystallization of a coarse-grained Nb-containing AISI 430 ferritic stainless steel. The material was processed by hot rolling and further annealed at 1250oC for 2 h to promote secondary recrystallization. Following, the material was cold rolled to a 80% reduction in thickness and annealed at 400-1000oC for 15 min. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) were used to characterize the microstructure. Recrystallization of this steel begins at 700oC. Important orientation effects were observed in both as-rolled and annealed conditions. Recrystallization kinetics was strongly dependent on the initial orientation of the coarse grains. Results show that grain boundaries, transition bands and coarse Nb(C,N) particles are preferential sites for nucleation at moderate annealing temperatures.


2007 ◽  
Vol 539-543 ◽  
pp. 4926-4931 ◽  
Author(s):  
A. Ferreira Filho ◽  
C. Herrera ◽  
Nelson Batista de Lima ◽  
R.L. Plaut ◽  
Angelo Fernando Padilha

The evolution of the crystallographic texture of ferritic stainless steels, starting from the as received (hot rolled) condition from the steel mill, going through cold rolling, annealing and final stamping is analyzed in this paper. Two ferritic stainless steels (Nb stabilized) having a thickness of 3.0 and 0.7mm, have been employed. The thicker one has been cold rolled to 40 and 73% thickness reduction, annealed at 750 and 850°C for 1 hour. The thinner one, with a similar composition, has been 77% cold rolled and annealed at 870°C at the steel plant and subsequently submitted to deep drawing in order to evaluate texture and drawability. Texture has been evaluated using DRX in the as received, cold rolled, annealed and after drawing conditions. Drawability has been evaluated using tensile testing in order to obtain the FLC curves. AISI 430 stainless steel, in the as received condition presented a strong {100} texture in the <110> and <120> directions and the gamma fiber. After cold rolling, the material presented stronger gamma and weaker alpha fibers. Annealing of the cold rolled samples conduced to the vanishing of the alpha and strengthening of the gamma fiber, adequate for deep drawing operations. In spite of the AISI 430 of 0.7mm having presented a strong gamma fiber, other deep drawing properties were not adequate and the material cracked during stamping.


Sign in / Sign up

Export Citation Format

Share Document