scholarly journals Reducing the flaws of 08Yu steel sheet blanks, designed for cold stamping products

Author(s):  
І. Doschechkina

The aim of the work is to develop a method of increasing the technological plasticity while maintaining the strength and preventing aging of blanks of cold-rolled sheet steel 08Yu. The task of this work is research and determination of optimal temperature-time parameters of high-speed contact recrystallization annealing and subsequent aging of 08Yu steel sheet blanks to obtain the required level of mechanical properties that would improve their deformability and ability of very deep drawing during cold stamping of products. The optimal parameters of the speed mode are set recrystallization annealing of cold-rolled 08Yu sheet steel, which provides the best structure and properties for further cold pressure treatment. The temperature-time modes of further aging and possibilities to prevent the processes of its natural aging during prolonged operation or transportation have been studied. The method and modes of heat treatment of blanks from finished 08Yu sheet steel to facilitate their deformability and improve stamping in order to reduce waste in the manufacture of products by cold deformatiion with deep and complex drawing were suggested.

2016 ◽  
Vol 46 (5) ◽  
pp. 364-367 ◽  
Author(s):  
I. V. Doshchechkina ◽  
S. S. D’yachenko ◽  
I. V. Ponomarenko ◽  
I. S. Tatarkina

1992 ◽  
Vol 31 (6) ◽  
pp. 535-537 ◽  
Author(s):  
Kazuo Koyama ◽  
Yoshikazu Matsumura ◽  
Shiroh Sanagi ◽  
Nobuhiko Matsuzu ◽  
Nobuyuki Kino
Keyword(s):  

2011 ◽  
Vol 298 ◽  
pp. 203-208 ◽  
Author(s):  
Zi Li Jin ◽  
Wei Li ◽  
Yi Ming Li

With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory,to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110}<UVW> texture components was enhanced and {100}<uwv> texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.


2005 ◽  
Vol 495-497 ◽  
pp. 363-368
Author(s):  
Soo Ho Park ◽  
Hyung Gu Kang ◽  
Yong Deuk Lee ◽  
Jae Chul Lee ◽  
Moo Young Huh

In order to investigate the effect of the reduction degree per rolling pass on the evolution of recrystallization textures and microstructures, the hot band of 17.5 Cr-1.1 Mo ferritic stainless steel sheets were cold rolled with lubrication according to two processing routes, by which different reduction degrees per pass were introduced. Rolling with a large number of passes led to the formation of fairly homogeneous rolling textures at all through-thickness positions. In contrast, cold rolling with large draughts resulted in pronounced texture gradients along the thickness direction. After recrystallization annealing, the texture maximum was obtained at {334}<483> in all samples regardless of the rolling routes and thickness layers. During subsequent annealing, recrystallization was observed to be faster in those grains with {111}<uvw> orientations, while it was retarded in grains having orientations close to {001}<110>.


2019 ◽  
Vol 944 ◽  
pp. 283-293
Author(s):  
Zhen Nan Cui ◽  
Yong Lin Kang ◽  
Guo Ming Zhu ◽  
Bao Shun Li ◽  
Quan Quan Qiu ◽  
...  

In this paper, a new type of automotive 1500 MPa grade hot-formed steel without boron but containing niobium was subjected to thermoforming experiments. The phase transition point and Continuous Cooling Transformation (CCT) curve of the hot-formed steel were measured by thermal dilatometer, and then the best austenitizing parameters was determined. The microstructure of the cold-rolled sheet and the hot-formed steel sheet were observed by electron microscopy. The microstructure of the steel sheet after hot forming was studied by X-ray diffraction (XRD) method to determine whether the microstructure after hot forming had residual austenite. The influence of residence conditions on its mechanical properties was studied. The experimental results has shown that the microstructure of the original cold-rolled sheet is mainly composed of ferrite and pearlite. After thermoforming, the basic microstructure are martensite and a small amount of ferrite; When the hot forming parameters is that 900 °C of the heating temperature, 3 min of the holding time, 8 s of the residence time, quenching temperature is the room temperature, the new 1500 MPa grade hot formed steel has the best mechanical properties that the tensile strength is 1519 MPa, the yield strength is 1060 MPa, the yield ratio is 0.73, and the elongation reaches 10.52%. The result shows that the new 1500 MPa grade hot formed steel could obtain excellent mechanical properties through a reasonable process under the premise of ensuring hardenability.


Author(s):  
S. W. Thompson

Fine carbide particles form in quenched-and-aged specimens of iron containing a small amount of carbon. Similar precipitation occurs in ferrite grains within dual-phase steels. The particles have been described as discs or loops, typically about 20 run in diameter and 2 nm thick, which lie on ﹛100﹜ planes within ferrite grains. The precipitates are believed to form in association with vacancies and produce increases in hardness and yield strength. Two studies showed that these features disappeared after heating specimens in the transmission electron microscope (TEM), and this note reports further on this phenomenon.Continuously annealed and cold-rolled sheet steel (provided by Inland Steel Company) contained (in wt pet) 0.087 C, 0.97 Mn, 0.27 Si, 0.034 Al, 0.008 S, and 0.005 N. Specimens were intercritically annealed at 770°C for five minutes and quenched in iced water. Tensile testing was conducted within one day of heat treatment, and then specimens were stored at room temperature for about six months. Thin foils were produced by conventional thinning methods and jet polished at 75 V and 80 mA in an electrolyte containing 95% acetic acid and 5% perchloric acid. Specimens were examined in a Philips EM400 operated at 120 kV.


2010 ◽  
Vol 638-642 ◽  
pp. 2781-2786
Author(s):  
Chang Shu He ◽  
Sadahiro Tsurekawa ◽  
Hiroyuki Kokawa ◽  
Xiang Zhao ◽  
Liang Zuo

An AC magnetic field (0.5Tesla) is applied with the field direction perpendicular to the rolling direction during annealing of a 76% cold-rolled IF steel sheet. Microstructure and texture evolution in the as-annealed specimens were determined using SEM based OIM technique. It is found that the recrystallization is noticeably retarded by AC magnetic field annealing. At the early stage of recrystallization (annealing at 650°C for 30min), the development of (111) <123> orientations was favored by the AC magnetic field. With progress of recrystallization (annealing at 700°C and 750°C for 30min), the applied AC magnetic field suppressed the development of γ-fiber recrystallization textures to some extent.


2007 ◽  
Vol 26-28 ◽  
pp. 27-31 ◽  
Author(s):  
Hao Liu ◽  
Ding Zhong Zhong ◽  
Long Qi Zhao ◽  
Tao Peng ◽  
Li Xin Wu ◽  
...  

The dilatometry curves and the critical phase transformation temperatures of high strength low-alloyed (HSLA) cold rolled sheet steel were determined by thermal simulation test machine. The samples were austenitized at 900°C,deformed at 40% of deformation and cooled at different rates of 0.1°C/s~ 60°C/s. The continuous cooling transformation (CCT) diagram under deformation condition can be drawn. The results showed that the critical phase transformation temperatures are as follows: Ac3=900°C, Ac1=735°C, Ar3=825°C, Ar1=695°C. A few amount of martensite in high strength low-alloyed cold rolled steel can be obtained at the cooling rate of 60°C/s. The experimental data provide the technical references for rolling control, cooling control and heat treatment in real production.


1985 ◽  
Vol 27 (9) ◽  
pp. 685-688
Author(s):  
A. N. Babitskaya ◽  
V. G. Mishchenko ◽  
V. S. Movshovich

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