Effects of cold-rolling reduction on the recrystallization texture and grain boundary of ferritic stainless steel

The study investigates the effects of cold-rolling reduction on the recrystallization-annealed Nb ＋ Ti stabilized ultra-pure ferritic stainless steel with 21% Cr in regards to its microstructure evolution, grain size,recrystallization texture, and grain boundary characteristic distribution and disorientation angle. The research employed the electron back scattered diffraction technique and its results have shown that the average grain size was reduced and the {111 / 〈 112 〉 component was strengthened,which rotated towards {5541 〈225 〉 and {4451 〈384 〉 ,with an increasing cold-rolling reduction. The number fraction of the low-angle grain boundary and the coincidence site lattice （CSL） boundary ,which was mainly made up of ∑3,∑7∑11 and ∑13b, also increased.

Effect of vanadium on the microstructure and properties of metastable austenitic stainless steel AISI 301LN

In this study,the effect of vanadium on the microstructure and properties of the metastable austenitic stainless steel AISI 301LN was investigated.Results of the study show that the addition of vanadium can refine grains and increase the strength of AISI 301LN by solution treatment.After 60%cold-rolling reduction,the microstructure of the steel was composed of work-hardened austenite bands and deformation-inducedɑ′martensite.Considerable work-hardening and phase transformation strengthening occurred.After cold rolling and subsequent annealing,the deformation-inducedɑ′martensite was reversed into fine-grained austenite.The work-hardened austenite bands underwent recrystallization;however,the structure of the recrystallized austenite grains was coarser than that of the reversed ones.Simultaneously,the strength of the experimental steels decreased with the increase in annealing temperature.The pinning effect of precipitates of vanadium inhibited the growth of austenite grains.Thus,the desirable combination of strength and ductility was obtained by grain refinement.

Effect of the cold deformation regime on microstructure and mechanical properties of AISI 301LN stainless steel

This study analyzed the effect of cold-rolling reduction （in a wide range of 10% - 80% ） and subsequent annealing on the microstructure and mechanical properties of AISI 301LN stainless steel. Results indicated the formation of shear bands and nucleation of strain-induced α＇-martensite at their intersections. The volume fraction of α＇-martensite increased with increase in cold-rolling reduction by the continuous growth of embryos. This, in turn,resulted in an increase in yield and tensile strengths. The reversion of α＇-martensite to austenite occurred after subsequent annealing. The observed variation in the grain size of reversed austenite can be related to the annealing regime. A good combination of strength and ductility can be obtained upon annealing at 650 ℃ for 30 min. The effect of grain size on yield strength conformed to the Hall-Petch relationship in the entire range of our analysis.

Mg-0.4Zn镁合金挤压板拉伸变形组织的演变

用电子背散射衍射(EBSD)技术结合原位拉伸,研究了在0%~20%应变条件下,Mg-0.4%Zn二元镁合金晶界、织构和裂纹的变化。结果表明,在拉伸应变从0%增加到20%的过程中,随着应变量的增大材料微观组织中的孪晶逐渐增加。孪晶的类型以{10-12}拉伸孪晶为主;这种孪生使材料的组织织构类型发生了显著的变化,随着应变量的增大(0001)//TD面的新织构组分的强度提高;微观裂纹优先在原始晶界和孪晶尖处萌生并在部分晶粒出现穿晶裂纹,随着应力的增大微裂纹进一步扩展并相互连接最终使材料断裂。