scholarly journals Influence of Martensite Deformation on Cu Precipitation Strengthening

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 282
Author(s):  
Jaromir Dlouhy ◽  
Pavel Podany ◽  
Ján Džugan

Cu precipitation strengthening was compared in steels after treatments with and without cold rolling. A 0.2% C steel containing up to 1.5% Cu was quenched and tempered. Cu precipitation took place during tempering and increased its yield strength (YS). Quenched and tempered samples were compared with samples where cold rolling was performed between quenching and tempering. They exhibited significantly different mechanical properties. In addition, Cu alloying influenced the properties of each group of samples in different ways. The quenched and tempered samples exhibited behavior that is typical of precipitation hardening. Cu caused yield strength to increase with tempering temperature and time. The cold rolling of martensite reduced the maximal Cu-related strengthening and also eliminated its time and temperature dependence.

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1815
Author(s):  
Feng Fang ◽  
Diwen Hou ◽  
Zhilei Wang ◽  
Shangfeng Che ◽  
Yuanxiang Zhang ◽  
...  

Based on conventional hot rolling processes and strip casting processes, Cu precipitation strengthening is used to improve the strength of non-oriented silicon steel in order to meet the requirements of high-speed driving motors of electric vehicles. Microstructure evolution was studied, and the effects of Cu precipitates on magnetic and mechanical properties are discussed. Compared with conventional processes, non-oriented silicon steel prepared by strip casting exhibited advantages with regard to microstructure optimization with coarse grain and {100} texture. Two-stage rolling processes were more beneficial for uniform microstructure, coarse grains and improved texture. The high magnetic induction B50 of 1.762 T and low core losses with P1.5/50, P1.0/400 and P1.0/1000 of 1.93, 11.63 and 44.87 W/kg, respectively, were obtained in 0.20 mm sheets in strip casting. Cu precipitates significantly improved yield strength over ~120 MPa without deteriorating magnetic properties both in conventional process and strip casting. In the peak stage aged at 550 °C for 120 min, Cu precipitates retained bcc structure and were coherent with the matrix, and the yield strength of the 0.20 mm sheet was as high as 501 MPa in strip casting. The main mechanism of precipitation strengthening was attributed to coherency strengthening and modulus strengthening. The results indicated that balanced magnetic and mechanical properties can be achieved in thin-gauge non-oriented silicon steel with Cu addition in strip casting.


2018 ◽  
Vol 284 ◽  
pp. 351-356 ◽  
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim A. Ryzhkov

The high strength aerospace steel alloyed with Cr, Mn, Si, Ni, W and Mo was studied. The austenite transformations under continuous cooling conditions were investigated using the dilatometer analysis at the cooling rates 0.1...30 °C/s. The mechanical properties of the studied steel were determined after the conventional quenching and tempering heat treatment. The dependences of the mechanical properties on the tempering temperature were obtained. The novel quenching and partitioning heat treatment was applied to the steel under consideration. The microstructure and the mechanical properties were studied after three different modes of the quenching and partitioning (QP) treatment: single-stage QP, two-stage QP and single-stage QP with subsequent tempering (QPT).


2012 ◽  
Vol 560-561 ◽  
pp. 655-660
Author(s):  
Li Juan Li ◽  
Li Hua Liu ◽  
Jing Wang

In order to guide atmosphere annealing process in industry, the effect of atmosphere and holding times on the surface quality and mechanical properties of the cold-rolling plate of Fe-42% Ni (4J42) was studied. It is found that in the laboratory, surface qualities of all the samples annealed at different annealing condition are all good enough. When the ratio of hydrogen and nitrogen is below 70%:30%, at different holding time, with increasing of H2 proportion, 4J42’s tensile strength and yield strength all increases, and the hardness declines. And except H2:N2=70%:30, when holding time is less than or equal to 1.2min, at different ratio of hydrogen and nitrogen, holding time will influence 4J42’s mechanical properties little. So combine requires in industry with the experiment results, it can be concluded that for 4J42 alloy, annealing at atmosphere of hydrogen nitrogen ratio is less than 70%:30% for about 1.2min is appropriate to atmosphere annealing process in industry.


2019 ◽  
Vol 944 ◽  
pp. 193-198
Author(s):  
Tian Yi Wang ◽  
Ren Bo Song ◽  
Heng Jun Cai ◽  
Jian Wen ◽  
Yang Su

The present study investigated the effect of cold rolling reduction on microstructure and mechanical properties of a 204C2 Cr–Mn austenitic stainless steel which contained 16%Cr, 2%Ni, 9%Mn and 0.083 %C). The 204C2 austenitic stainless steels were cold rolled at multifarious thickness reductions of 10%, 20%, 30%,40% and 50%, which were compared with the solution-treated one. Microstructure of them was investigated by means of optical microscopy, X-ray diffraction technique and scanning electron microscopy. For mechanical properties investigations, hardness and tensile tests were carried out. Results shows that the cold rolling reduction induced the martensitic transformation (γ→α ́) in the structure of the austenitic stainless steel. With the increase of the rolling reduction, the amount of strain-induced martensite increased gradually. Hardness, ultimate tensile strength and yield strength increased with the incremental rolling reduction in 204C2 stainless steels, while the elongation decreased. At the thickness reduction of 50%, the specimen obtained best strength and hardness. Hardness of 204C2 stain steel reached 679HV. Ultimate tensile strength reached 1721 MPa. Yield strength reached 1496 MPa.


2018 ◽  
Vol 765 ◽  
pp. 149-154 ◽  
Author(s):  
Seung Min Oh ◽  
Sun Ig Hong

Microstructure and mechanical properties of cast and cold-rolled equitomic CoCrFeCuNi alloy in which Mn was substituted by Cu from Cantor alloy was studied. The separation into two solid solutions (Cr-Co-Fe rich and Cu-rich phases) were observed in CoCrFeCuNi. Coarsening and widening of interdendritic Cu-rich phase after homogenization was observed after homogenization, suggesting Cu-rich phase is thermodynamically stable. The compressive stress-strain curves of homogenized cast CoCrFeCuNi alloy exhibited the reasonably high strength and excellent deformability for the cast alloy. The yield strength increased up to 960MPa after cold rolling from 265MPa of the homogenized cast alloy. The significant increase of yield strength is thought to be associated with the alignment of Cu-rich second phase in addition to cold work dislocation storage after cold rolling.


2011 ◽  
Vol 142 ◽  
pp. 95-98
Author(s):  
Jian Sheng Ding ◽  
Lin Xun Liu ◽  
Jin Chun Feng

The supercritical material F92 steel is regarded as the research object, and the influence law of heat treatment process on its tissue and properties is analyzed. The results show that when the temperature of heat treatment quenching and tempering is too low, a large number of alloying elements cannot be fully integrated into the austenite, and the optimal obdurability of F92 steel is still not fully exploited; while too high temperature of heat treatment quenching and tempering will weaken the strength, plasticity and toughness. When F92 steel is processed by heating quenching at 1050 °C and tempering at 680 °C, its tissue is the smaller tempered lath martensite. The carbide is precipitated, generating precipitation strengthening, which gives it a high rupture strength and toughness. F92 steel is with high mechanical properties when heating quenched at 1050 °C and tempered 680 °C.


2014 ◽  
Vol 936 ◽  
pp. 1796-1800
Author(s):  
Peng Dang ◽  
Xiao Wei Zhang ◽  
Yun Wang ◽  
Qing Zhang ◽  
Chang Liang Li

The influence of annealing temperature on the microstructure, mechanical properties and corrosion resistant of cold rolling zirconium sheet were studied in the manuscript. The experimental results shown that the tensile strength and yield strength of zirconium sheet were decreased and the elongationwas raised with the raising of annealing temperature from 500 °C to 580 °C. The recrystallization are not happened in zirconium sheet at the annealing temperature of 500 °C. Zirconium sheet complete recrystallized and the strength and elongation get a well match at the annealing temperature of 540°C. Zirconium sheet also complete recrystallized at the annealing temperature of 580°C but the crystalline grain has the tendency of growing. The annealing temperature has no effect on the corrosion resistant of zirconium sheet.


Author(s):  
Pradipta Kumar Jena ◽  
K. Siva Kumar ◽  
A.K. Singh

This work describes the microstructure, texture and anisotropy in mechanical behavior of a high strength steel in various tempered conditions. The microstructures and mechanical properties change considerably with varying tempering temperatures. The material exhibits low in-plane anisotropy and low anisotropic index in terms of yield strength and elongation with increase in tempering temperature. The anisotropy of the material displays similar behavior to that of the yield strength.


Author(s):  
S. A. Golosienko ◽  
N. A. Minyakin ◽  
V. V. Ryabov ◽  
T. G. Semicheva ◽  
E. I. Khlusova

The work covers the effect of niobium, as well as niobium and vanadium together, on mechanical properties of high-strength chromium-nickel-molybdenum steel after thermal improvement (heat treatment). The mechanical properties of steels are determined after applying various tempering temperatures (from 580 to 660°C), durations of tempering (from 1 to 16 hours), and also after quenching from rolling heat and furnace heat with subsequent tempering. It is shown that after quenching and tempering in the temperature range 580– 660°C, simultaneous microalloying by niobium and vanadium, compared to microalloying by niobium alone, increases the yield strength but in significantly decreases toughness and ductility. Quenching from rolling heat increases strength while maintaining high toughness and the increase in strength is most noticeable for steel microalloyed only by niobium.


2021 ◽  
Vol 410 ◽  
pp. 221-226
Author(s):  
Mikhail V. Maisuradze ◽  
Maxim A. Ryzhkov ◽  
Dmitriy I. Lebedev

The features of microstructure and mechanical properties of the aerospace high strength steel were studied after the implementation of various heat treatment modes: conventional oil quenching and tempering, quenching-partitioning, austempering. The dependence of the mechanical properties on the tempering temperature was determined. The basic patterns of the formation of mechanical properties during the implementation of isothermal heat treatment were considered. The optimal heat treatment conditions for the studied steel were established.


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