Press-Shaving Characteristics of Ultrahigh-Strength Steel Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 1879-1886 ◽  
Author(s):  
Masao Murakawa ◽  
Kenta Nakamura ◽  
Tomio Shionome ◽  
Fumitoshi Komuro ◽  
Giichirou Muro ◽  
...  
Keyword(s):  
Surface Quality ◽  
New Technologies ◽  
High Strength ◽  
Process Conditions ◽  
Steel Sheets ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel ◽  
Experimental Researches ◽  
Very High

The paper proposes new technologies able to improve the surface quality in the case of press-shaving applied to very high strength materials. Experimental researches were developed and the best combination of process conditions was identified.

Hot Stamping and Press Quenching of Ultrahigh Strength Steel Sheet Using Resistance Heating

2007 ◽  
Vol 344 ◽  
pp. 309-316 ◽  
Author(s):  
Seijiro Maki ◽  
Atsushi Hamamoto ◽  
Shouichi Saito ◽  
Kenichiro Mori
Keyword(s):  
Steel Sheet ◽  
Heating Temperature ◽  
Hot Stamping ◽  
High Strength ◽  
Resistance Heating ◽  
Input Energy ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel ◽  
Ac Power ◽  
Hardness Property

The feasibility of hot stamping and press quenching of ultrahigh strength steel sheet using resistance heating was investigated by demonstrating experiments. In the experiments, a rectangular blank of high strength steel sheet, SPFC980Y, 1.2mm thick, 20mm wide and 130mm long was used and it was resistance-heated with a pair of parallel electrodes placed 120mm away from each other, using an AC power supply with a function of input energy control. The relationship between input energy and heating temperature was examined and then hot stamping and press quenching performances were examined. The press quenching was also experimented in hot hat-shaped bending, and the influences of the heating temperature on spring-back and hardness property were investigated. The results of the experiments revealed that hot stamping and press quenching using resistance heating are highly feasible.

scholarly journals Smooth Hole Piercing of Ultrahigh-strength Steel Sheets by Means of Press-shaving

2016 ◽  
Vol 57 (663) ◽  
pp. 366-368
Author(s):  
Akira HARAI ◽  
Manabu SUZUKI ◽  
Akira MATSUMOTO ◽  
Fumitoshi KOMURO ◽  
Tomio SHIONOME ◽  
...  
Keyword(s):  
Steel Sheets ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel

scholarly journals Precision Piercing and Blanking of Ultrahigh-strength Steel Sheets

2014 ◽  
Vol 81 ◽  
pp. 1114-1120 ◽  
Author(s):  
Masao Murakawa ◽  
Manabu Suzuki ◽  
Tomio Shionome ◽  
Fumitoshi Komuro ◽  
Akira Harai ◽  
...  
Keyword(s):  
Steel Sheets ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel

Prevention of Oxidation in Hot Stamping of Ultra High Strength Steel Sheets

2009 ◽  
Vol 410-411 ◽  
pp. 255-261 ◽  
Author(s):  
Kenichiro Mori ◽  
Seijiro Maki ◽  
Shouichi Saito
Keyword(s):  
High Strength Steel ◽  
Elevated Temperatures ◽  
Hot Stamping ◽  
High Strength ◽  
Shape Accuracy ◽  
Steel Sheets ◽  
Ultra High Strength Steel ◽  
Bending Load ◽  
Formed Product ◽  
Very High

Oxidation in hot stamping of ultra high strength steel sheets was prevented by coating the sheets with an oxidation preventive oil. For four types of oxidation preventive oil, the degree of oxidation under natural cooling of the heated sheets without forming was first evaluated. The oil that forms a liquefied film at elevated temperatures exhibited high oxidation prevention, and this oil was chosen for a hot bending experiment. Hot hat-shaped bending of the coated sheets using resistance heating was carried out to examine the properties of the products. The bending load was markedly decreased, the shape accuracy of bent products was very high, the surface roughness was similar to that of the sheet, and the hardness was about 1.5 times larger than that of the sheet before the bending due the die quenching. In addition, the layer remaining on the surface of the formed product could be removed using phosphoric acid. It was found that the hot stamping operation using the oxidation preventive oil is effective in the precision forming of ultra high strength steel sheets.

ISPAT INLAND DI-FORM 140T

Alloy Digest ◽  
2003 ◽  
Vol 52 (6) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
High Ductility ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel

Abstract Di-Form 140T is an ultrahigh-strength steel that offers a combination of high strength and high ductility, making it an excellent choice for parts consolidation programs. This datasheet provides information on composition, physical properties, and tensile properties. Filing Code: CS-137. Producer or source: Ispat Inland.

scholarly journals Deformation Characteristics of Ultrahigh-Strength Concrete under Unrestrained and Restrained States

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Joo-Ha Lee ◽  
Kwang-Mo Lim ◽  
Doo-Yeol Yoo ◽  
Nam-Hyoung Lim
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Concrete Specimen ◽  
Ring Test ◽  
Specimen Thickness ◽  
Cracking Behavior ◽  
Strength Concrete ◽  
Ultrahigh Strength ◽  
Very High

As structures like skyscrapers and long-span bridges become larger, the demand for higher strength of concrete is increasing. However, research on ultrahigh-strength concrete (UHSC) is still in its infancy. In particular, UHSC is known to have a considerably higher level of autogenous shrinkage than normal strength concrete (NSC), and the possibility of cracking at an early age is very high. Therefore, in this study, shrinkage and cracking behavior of high-strength concrete (HSC), very-high-strength concrete (VHSC), and UHSC were evaluated through unrestrained shrinkage test and restrained shrinkage test (ring test). The primary experimental variables are the compressive strength level according to the water-to-binder ratio (W/B), fly ash content, and concrete specimen thickness. The experimental results demonstrated that the drying shrinkage decreased as the W/B ratio and the fly ash replacement ratio increased, and the restraint cracks appeared to be the earliest and most brittle in the UHSC with the smallest W/B. Increased concrete thickness and incorporation of fly ash were observed to inhibit crack initiation effectively.

Effect of the Welding Thermal Cycles Based on Simulated Heat Affected Zone of S1300 Ultrahigh Strength Steel

2021 ◽  
Vol 890 ◽  
pp. 33-43
Author(s):  
Judit Kovács ◽  
János Lukács
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel ◽  
Strength And Toughness

In the automotive industry there is an increasing demand for the wider application of high strength steels due to their favourable mechanical properties. The steel producers continuously developing new generations of high strength steels to insure higher strength and toughness properties. Since in most cases these steels are joined in welded structures, great attention must be taken to their weldability. The weldability of high strength steels has still challenges which are as follows: cold cracking sensitivity; reduction of strength and toughness of heat affected zone (HAZ); filler metal selection. Because the mechanical properties of ultrahigh strength steels are provided by using various alloying elements, micro alloys, and by different metallurgical methods, the steels may lose their outstanding properties during welding. In real welded joints the critical parts of the HAZ have small extent so their properties can be limitedly analysed by conventional material testing methods. With the help of physical simulators, the different parts of the heat affected zone can be produced in an adequate size for subsequent tests. In our research work the weldability, especially the HAZ properties of an ultrahigh strength structural steel (Rp0.2 = 1300 MPa) were investigated on thermal simulated samples with the help of Gleeble 3500 physical simulator. Three relevant technological variants for gas metal arc welding (GMAW), t8/5 = 5 s, 15 s and 30 s were applied during the HAZ simulations in the selected coarse-grained (CGHAZ), intercritical (ICHAZ) and intercritically reheated coarse-grained (ICCGHAZ) zones. Both the microstructure was studied by optical microscope and the mechanical properties were analysed by Vickers hardness tests and Charpy V-notch impact tests at -40 °C. According to the results the investigated ultrahigh strength steel was softened on account of the welding heat cycles, besides that the strength of the investigated ultrahigh strength steel can be better with the application of shorter t8/5 cooling time.

scholarly journals Decarburizing Behavior and Its Effect on Mechanical Properties of Ultrahigh Strength Steel Sheets

2021 ◽  
Vol 61 (4) ◽  
pp. 1300-1308
Author(s):  
Kentaro Kuwata ◽  
Yoshito Takemoto ◽  
Mitsuhiro Okayasu ◽  
Jian Bian ◽  
Takehide Senuma
Keyword(s):  
Mechanical Properties ◽  
Steel Sheets ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel
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