scholarly journals Study on rolling process and heat treatment of high strength ship plate steel EH40

10.30544/372 ◽  
2018 ◽  
Vol 24 (3) ◽  
pp. 199-208 ◽  
Author(s):  
Chunquan Liu ◽  
Qichun Peng ◽  
Zhengliang Xue

Means of a tensile test studied the mechanical properties and microstructure of the experimental steel plate under different rolling processes, Charpy impact test, optical microscopy and scanning electron microscopy (SEM). The results show that the optimum thermomechanical control process (TMCP) is a heating temperature of 1200 °C, the best rolling temperature of 1180 °C. The thickness of the ship plate steel was rolled from 170 mm to 40 mm in the recrystallization zone by multi-channel time deformation, and then the thickness was decreased from 40 mm to 15mm in the non-recrystallization zone, the temperature waiting for a range 980 °C ~ 920 °C, the finish rolling temperature of 830 °C. After rolling and being cooled rapidly by laminar cooling, the cooling rate is about 12 °C/s and the final target temperature of 600 °C, which maintains the best state of steels. All data of the experimental steels have accelerated the international level, high-strength ship plate EH40 has been successfully trialed and met the practical requirements, all of these provide a solid foundation for further scientific research.

1988 ◽  
Vol 110 (3) ◽  
pp. 171-176
Author(s):  
Y. Nakano ◽  
Y. Saito ◽  
K. Amano ◽  
M. Koda ◽  
Y. Sannomiya ◽  
...  

This paper describes the metallurgical approaches for producing 415MPa and 460MPa yield strength offshore structural steel plates and the mechanical properties of the steel plates and their welded joints. A thermo-mechanical control process (TMCP) was adopted to manufacture YP415MPa and YP460MPa steel plates with weldability comparable to conventional YP355MPa steel plates. The Charpy impact and CTOD tests of the steel plates and their welded joints proved to be very good.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1885-1890 ◽  
Author(s):  
ZUOCHENG WANG ◽  
GUOTAO CUI ◽  
TAO SUN ◽  
WEIMIN GUO ◽  
XIULING ZHAO ◽  
...  

In our research, boron was added into the Nb -added high strength low alloy (HSLA) H -section steels. The contents of boron added were 4ppm, 8ppm and 11ppm, respectively. The mechanical properties of H -section steels with/without boron were examined by using uniaxial tensile test and Charpy impact test ( V -notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results indicate that boron gives a significant increase in impact toughness, especially in low temperature impact toughness, though it leads to an unremarkable increase in strength and plasticity. For instance, the absorbed energy at -40°C reaches up to 126J from 15J by 8ppm boron addition, and the ductile-brittle transition temperature declines by 20°C. It is shown that boron has a beneficial effect on grain refinement. The fracture mechanism is transited from cleavage fracture to dimple fracture due to boron addition.


2012 ◽  
Vol 557-559 ◽  
pp. 2355-2360 ◽  
Author(s):  
Min Jiang ◽  
Li Na Chen ◽  
Wei Pang ◽  
Chong He Li ◽  
Xiong Gang Lu

A novel pipeline steel was prepared by the vacuum inducting technology, using Gleeble-3500 hot simulator, its parameters of thermo-mechanical control process (TMCP), such as heating temperature, finish rolling temperature, finish cooling temperature and cooling rate, have been studied by the orthogonal experiment with four factors and three levels. Through the orthogonal theoretical analysis, it is found that the sequence of the effect of parameters on the mechanical property is: Cooling rate > Heating temperature > Finish cooling temperature > Finish rolling temperature, the cooling rate is the most important factor affecting the inspection target and possesses a great influence on the hardness of the pipeline steel.


2018 ◽  
Vol 32 (6) ◽  
pp. 729-745 ◽  
Author(s):  
Olivier De Almeida ◽  
Jean-François Ferrero ◽  
Laurent Escalé ◽  
Gérard Bernhart

The aim of the work is to use Charpy impact test for quick evaluations of different Polyether-ether-ketone (PEEK)-reinforced composites to be used for impact protection. In the first part, the influence of weave pattern was first analysed by comparing the impact behaviour of three PEEK composites reinforced with plies of unidirectional (UD) tapes, 5H satin fabrics and 2 × 2 twill fabrics made of high-strength carbon fibres. In the second part, the influence of fibre nature was investigated for the same weave pattern. The impact behaviour of five 2 × 2 twill fabrics made from inorganic fibre (carbon, glass and basalt) and organic fibre (aramid and poly(p-phenylene-2,6-benzobisoxazole) (PBO)) has been compared. Two main types of failure modes were identified: a brittle behaviour mode with high failure strength and a highly deformable behaviour mode in which energy absorption is more important. The balance between brittle behaviour and highly deformable behaviour results from competition between the yarn crimp, weave pattern and fibre properties of the composite. Slight yarn crimp and small ply thickness increase the stiffness of the composite and induce brittle behaviour characterized by fibre failure in tension and a steep peak on the loading curves. This behaviour is observed in UD and 5H satin carbon-reinforced composites or 2 × 2 twill glass and basalt fabric-reinforced composites. In contrast, aramid and PBO 2 × 2 twill fabric composites exhibit high shear strength. The highly deformable behaviour of the specimens during the Charpy impact led, in the case of organic fibres, to a non-breakage of the fibres and consequently to a high level of energy absorption. This behaviour is necessarily interesting in armour applications.


2014 ◽  
Vol 782 ◽  
pp. 57-60
Author(s):  
Stanislava Hlebová ◽  
Ladislav Pešek

Currently only few methods exist for thin steel sheet testing, especially based on fracture mechanics concept. Charpy impact test is one of the most used method for testing notch toughness and fracture behaviors because of the simplicity and the other advantages [. This article deals with toughness testing of automotive ultra high strength steel sheets (UHSS). Several standard types of toughness test that generate data for specific loading conditions and/or component design approaches exist. Two definition of toughness will be discussed: i) Charpy V-notch toughness, method includes joining of thin steel sheets to one compact unit and ii) material (tensile) toughness [. Two steels were used, DP1000 and 1400M of 1,8 mm thickness and two joining techniques: bonding with adhesives and joining with holders. Effect of material, joining technology, structural adhesives, and number of joined plates on the toughness values was quantified at the room temperature. Toughness of steels by the tensile test was added for comparison. Fracture surface was observed using scanning electron microscope analysis.


2015 ◽  
Vol 816 ◽  
pp. 743-749 ◽  
Author(s):  
Xiao Long Yang ◽  
Xiao Dong Tan ◽  
Yun Bo Xu ◽  
Zhi Ping Hu ◽  
Yong Mei Yu ◽  
...  

Based on TMCP and UFC technology, the microstructures and impact toughness of low carbon bainitic steel were studied in this paper. The bainite morphology and fracture surfaces of Charpy impact specimens were observed by SEM, and mechanical properties of bainitic steel were measured by tensile and impact test. The results showed that the yield and tensile strengths of steel were 804MPa and 1015MPa, and elongation was 15.7% when the rolling was finished in the austenite recrystallization region. The steel rolled below Tnr temperature obtained tht yield strength of 930 MPa, tensile strength of 1090 MPa and elongation of 16.2%. However, the impact toughness was deteriorated in the steel rolled above Tnr temperature while the excellent impact toughness existed in the steel rolled below Tnr temperature. The impact toughness of steel rolled below Tnr temperature was 140J at-60°C, while the impact toughness of 15J at the same temperature was obtained for the steel rolled above Tnr temperature. The large cleavage fracture region on the fracture surface occured with the decrease of tested temperature in the steel rolled above Tnr temperature and inevitably reduced the impact toughness, while the main ductile fracture existed in the steel rolled below Tnr temperature at the same temperature. The rolling process of steel can strongly affect impact toughness of low carbon bainitic steel. Hence, the different rolling processes can adjust the occurrence of cleavage fracture and ductile fracture in order to improve the impact toughness.


2013 ◽  
Vol 390 ◽  
pp. 547-551 ◽  
Author(s):  
K.Emre Öksüz ◽  
Hanlar Bağirov ◽  
Mehmet Şimşir ◽  
Ceyhun Karpuzoğlu ◽  
Aykut Özbölük ◽  
...  

Aluminum alloys have been extensively used as structural material due to its high strength and damage-tolerance. Alloy 6061, 2024 and 7075 are engineered to be lightweight and strong,and their ease of formability allows complex shapes and drawn parts,which can then be further enhanced with heat treating. In this study is aimed to improve the mechanical properties of aluminum alloys by heat treatment.AA2024 and AA7075 were selected and each alone at T3 and T6 temper conditions has been studied respectively.For the mechanical properties of AA2024 and AA7075 alloyshardness, fatigue behavior, tensile test and charpy impact test with standard V notched specimens at RTand-5 °C were analysed in the present study. Microstructural characterization has been done using standard metallography.


2018 ◽  
Vol 941 ◽  
pp. 453-457
Author(s):  
Hiroyuki Kawata ◽  
Osamu Umezawa

The steels consisting of multi-phase structure show an advantage for their high strength and good formability. The ductile to brittle transition with decreasing temperature has been investigated by Charpy impact test with sub-size specimen for the ferrite + pearlite structure steel sheet. The transition curve of the absorbed energy showed a two-step transition behavior, and the “middle shelf” appeared clearly in the curve. The cleavage-like fracture with few dimples appeared on the fracture surface of the specimens at the middle shelf, and the plastic strain was detected just below the fracture surface. This result suggested that the fracture at the middle shelf propagates with the quasi-cleavage fracture accompanied with plastic deformation. Although the traces of fracture surface corresponded to (001), (011), and (112) bcc-iron planes, the (001) cleavage plane was not dominant for the fracture propagation path at the middle shelf.


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