scholarly journals EXPERIMENTAL INVESTIGATION OF SPRINGBACK OF LOCALLY HEATED ADVANCED-HIGH STRENGTH STEELS

2021 ◽  
Vol 9 (3) ◽  
pp. 269-277
Author(s):  
Omer Eyercioglu ◽  
Sevket Alacaci ◽  
Mehmet Aladag
Keyword(s):  
Heating Temperature ◽  
Local Heating ◽  
High Strength Steels ◽  
High Strength ◽  
Hot Forming ◽  
Spring Back ◽  
Cold Forming ◽  
Advanced High Strength Steels ◽  
Forming Temperature ◽  
Bending Loads

Sheet metal bending is one of the important metals forming processes at ambient temperature. The usage of high-strength steel is one of the stronger materials for the construction of components in the automotive industries. However, for complex shapes, cold forming is not always sufficient, and heating the workpiece plays a major role in manufacturing these shapes. Bendability may increase with increasing forming temperature and currently, hot forming of advanced high strength steels (AHSS) is becoming more attractive. While hot forming of AHSS is beneficial for high formability, subsequent quenching is required to maintain final strength. This procedure extends the production time. In this study, temperature gradients, bending loads, and springback after V-bending were investigated. The experimental study was carried out on a 2 mm thick Docol 1500M steel at various temperatures by using a speed-controlled servo press machine. The bending regions of the specimens were locally heated to 200, 300, 400, 500, and 600oC by using a high-frequency induction heating device. The results show that; punch loads were significantly lowered with increasing the local heating temperature during bending. There were no cracks observed on the specimens. The amount of spring back is decreasing with the bending temperature and around 500oC almost no springback was measured. Negative spring back was observed for the bending temperatures higher than 500oC

DOMEX 1200

Alloy Digest ◽  
2009 ◽  
Vol 58 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Heavy Vehicles ◽  
Cold Forming ◽  
Advanced High Strength Steels ◽  
Minimum Yield

Abstract Domex 1200 is a member of the Domex family of cold-forming steels, which are thermomechanically rolled and where all the processing is carefully controlled. The alloy is used in cold-formed and welded products and has a minimum yield strength of 1200 MPa (174 ksi). The Domex alloys are advanced high-strength steels that reduce the weight of heavy vehicles, trailers, cranes, and containers. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-605. Producer or source: SSAB Swedish Steel Inc.

DOMEX 960

Alloy Digest ◽  
2009 ◽  
Vol 58 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Heavy Vehicles ◽  
Cold Forming ◽  
Advanced High Strength Steels ◽  
Minimum Yield

Abstract Domex 960 is one fo the Domex family of cold-forming steels, which are thermomechanically rolled and where all the processing is carefully controlled. The alloy is used in cold-formed and welded products and has a minimum yield strength of 960 MPa (140 ksi). The Domex alloys are advanced high-strength steels that reduce the weight of heavy vehicles, trailers, cranes, and containers. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-603. Producer or source: SSAB Swedish Steel Inc.

DOMEX 700W

Alloy Digest ◽  
2014 ◽  
Vol 63 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Resistant Steel ◽  
Bend Strength ◽  
Heavy Vehicles ◽  
Cold Forming ◽  
Advanced High Strength Steels

Abstract Domex 700W is an extra high strength member of the Domex family of cold-forming steels, which are thermomechanically rolled and where all the processing is carefully controlled. The Domex alloys are advanced high-strength steels that reduce the weight of heavy vehicles, trailers, cranes, and containers. The "W" signifies a weather-resistant steel. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SA-705. Producer or source: SSAB Swedish Steel Inc..

Design of Modern Steels for Automotive Application

2010 ◽  
Vol 638-642 ◽  
pp. 3111-3116 ◽  
Author(s):  
Harald Hofmann ◽  
Thomas Heller ◽  
Sascha Sikora
Keyword(s):  
High Strength Steels ◽  
Superplastic Forming ◽  
High Strength ◽  
Hot Forming ◽  
Automotive Application ◽  
Advanced High Strength Steels ◽  
Automobile Components ◽  
Multi Phase ◽  
Further Development ◽  
Complex Parts

Advanced high-strength steels offer a great potential for the further development of automobile bodies-in-white due to their combined mechanical properties of high formability and strength. New types of grades – multi-phase steels, superductile steels and density reduced steels – are under development at ThyssenKrupp Steel with tensile strength levels of up to 1000 MPa in combination with excellent formability for the high demands of cold formed structural automobile components. New forming technologies at increased temperatures – hot forming, semi-hot forming and superplastic forming - enable the processing of complex parts with extreme high strength. ThyssenKrupp Steel identifies potential future steels and technology concepts by technology monitoring and evaluates their potential for future applications in pre-development projects. University research institutions are significantly involved in this essential future oriented challenge. Seminal concepts are being implemented together with automotive manufactures by simultaneous engineering processes with coordinated phases of production and testing.

Comparison of Material Behavior and Economic Effects of Cold and High Temperature Forming Technologies Applied to High-Strength Steels

2005 ◽  
Vol 6-8 ◽  
pp. 101-108 ◽  
Author(s):  
Reimund Neugebauer ◽  
Angela Göschel ◽  
Andreas Sterzing ◽  
Petr Kurka ◽  
Michael Seifert
Keyword(s):  
Elevated Temperatures ◽  
High Strength Steels ◽  
Dimensional Accuracy ◽  
High Strength ◽  
Economic Effects ◽  
Material Behavior ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming ◽  
Forming Tools

The focus of forming high-strength steel at elevated temperature is to improve its forming properties like elongation and to reduce the power requirements during the forming process in opposite to cold forming. Because of the undefined and large spring-back effects parts made by cold forming are not able to achieve the demanded dimensional accuracy, which is necessary for laser welding operations in car body assembly. The reduction of the spring-back behavior is another advantage of the temperature controlled forming technology. On the other side the forming at elevated temperatures requires increased costs for forming tools and tempering equipment. For a fundamental evaluation of this technology, expenditures for the complete process chain have to be considered.

scholarly journals Investigation Effect of Spring Back on Bending Test of (DP590) Dual Phase Steel

2018 ◽  
Vol 2 (6) ◽  
pp. 55-62
Author(s):  
Muhamad Sani Buang ◽  
Keyword(s):  
Sheet Metal ◽  
Dual Phase Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Bending Test ◽  
Dual Phase ◽  
Spring Back ◽  
Factors Affecting ◽  
Advanced High Strength Steels ◽  
Fitting In

: The use of advanced high strength steels as a metal in sheet metal forming in automotive industry currently has been increased where Advanced High Strength Steel (AHSS) especially Dual Phase (DP590) Steels have gained a great attention due to a combination of high strength and good formability. However, one of the major constraints in forming AHSS is the occurrence of high spring back caused by elastic relaxation after loading, which causes illness-fitting in part assembly and geometric deviation of the intended design. Spring back is the main problem of defect that occurs at sheet metal after the bending process which creates problems for the parts during the assembly. This paper presents an investigation the effect of spring back on bending test of Dual Phase Steel (DP590). Punch travel and thickness are among factors affecting the spring back behavior. Various parameter value; punch radius (5mm), die radius (5mm), die gap (70mm), thickness of specimen 1mm and 2mm, punch travel/stroke (25%, 50%, 75%, 100%) from 20 mm depth, punch speed (2mm/min) and Orientation of sheet cutting, which is in rolling (00°), diagonal (45°) and transverse (90°). From the analysis of V-bending test punch travel, thickness and orientation of sheet cutting are significant factor that affecting the spring back phenomena. The result form this experiment could be useful for design engineers and manufacturing engineers to make improvement of predict the spring back behavior and also to understanding the material properties of AHSS in order to eliminate spring back and achieve good final product.

DOMEX 550W

Alloy Digest ◽  
2013 ◽  
Vol 62 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Resistant Steel ◽  
Bend Strength ◽  
Heavy Vehicles ◽  
Cold Forming ◽  
Advanced High Strength Steels

Abstract Domex 550W is an extra high strength member of the Domex family of cold-forming steels, which are thermomechanically rolled and where all the processing is carefully controlled. The alloy is used in cold formed and welded products. The Domex alloys are advanced high-strength steels that reduce the weight of heavy vehicles, trailers, cranes, and containers. The "W" signifies a weather resistant steel. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-688. Producer or source: SSAB Swedish Steel Inc..

Spring-Back Prediction of U-Channel Stamping with Martensite Transformation

2010 ◽  
Vol 146-147 ◽  
pp. 1265-1269
Author(s):  
Wen Jiao Dan ◽  
Wei Gang Zhang ◽  
Shu Hui Li
Keyword(s):  
Volume Fraction ◽  
High Strength Steels ◽  
High Strength ◽  
Deformation Energy ◽  
Trip Effect ◽  
Spring Back ◽  
Rate Condition ◽  
Advanced High Strength Steels ◽  
Automotive Body ◽  
Back Angle

As an advanced high strength steels, transformation-induced plasticity (TRIP) steel has obtained more and more attentions in automotive body components forming. The TRIP effect of this steel can improve the strength of the material, which results in the spring-back angle is different with that without TRIP effect. In this paper, the spring-back process of U-channel stamping with TRIP effect is studied by deformation energy method, which is based on a constitutive model accompanying strain-induced transformation in strain rate condition. The results have shown that martensite volume fraction distribution in key parts is related to the deformation energy of material, which induces the spring-back angle higher than those without TRIP.

Design and Properties of 1000 MPa Strength Level Hot-Formed Steels Possessing Dual-Phase and Complex-Phase Microstructures

2018 ◽  
Vol 941 ◽  
pp. 352-357 ◽  
Author(s):  
Maribel Arribas ◽  
Radhakanta Rana ◽  
Chris Lahaije ◽  
Xabier Gómez ◽  
Iñigo Aranguren ◽  
...  
Keyword(s):  
Lightweight Design ◽  
High Strength Steels ◽  
High Strength ◽  
Total Elongation ◽  
The Body ◽  
Hot Forming ◽  
Dual Phase ◽  
Complex Phase ◽  
Cold Forming ◽  
Martensite Content

In cold forming for automotive lightweight design, advanced high strength steels (AHSS) lead to limited formability, high springback and press forces, low stretch flangeability, multiple operations for complex geometries and large scrap rates. Two sets of AHSS, namely ferritic-martensitic dual-phase (DP) steel and martensitic-bainitic complex-phase (CP) steel with some amounts of retained austenite (RA), were designed for the hot-forming route, which eliminates the above drawbacks and guarantees higher performance in the body-in-white (BIW). Design of four DP and four CP alloys was accomplished using JMatPro6.0 thermodynamic software and available literature. The alloys were manufactured in the laboratory in cold-rolled gauge of ~1.5 mm and subjected to hot-forming cycles including hot deformation (up to 20% strain), using a dilatometer and a Gleeble 3800 machine. The thermal cycles of the DP alloys included an intercritical reheating whereas in-situ austempering or slow continuous cooling followed by supercritical reheating was used for the CP alloys. The results showed that yield strength (YS) of 605MPa & 695MPa, ultimate tensile strength (UTS) of 1097MPa & 1242MPa with a total elongation (TE) of 12.6% & 14.1% can be achieved in the best performing DP alloys with a martensite content of 65% & 60 vol.%. The best CP alloys with austempering achieved YS of 673MPa & 699MPa, UTS of 983MPa & 1026MPa and TE of 9.2% & 13.6% with RA of 4%-12 vol.%. The continuously-cooled alloys achieved even better properties. Higher bendability at 1.0 mm gauge in the critical direction was achieved in the CP alloys (90o&107o) than in the DP alloys (73o&76o).

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