scholarly journals Experimental Investigation of Process Forces and Part Quality for Fine Blanking of Stainless Steel with Inductive Heating

2021 ◽  
Author(s):  
Ingo Felix Weiser ◽  
Robby Mannens ◽  
Andreas Feuerhack ◽  
Thomas Bergs
Keyword(s):  
Stainless Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Martensite Phase ◽  
Inductive Heating ◽  
Fine Blanking ◽  
Quality Properties ◽  
Process Forces ◽  
Die Roll ◽  
Blanking Process

Fine blanking is a highly productive process of industrial mass production with which high quality components in particular but not exclusively for the automotive industry are produced. The manufacturing process faces its limits at elevated tensile strengths of the materials to be processed. Consequently, high-strength steels can currently only be fine blanked to a limited extent. This can be overcome by lowering the flow stress of high-strength steels by means of inductive heating. A steel of high importance especially for industries with high hygiene standards such as medical and nutrition production is the stainless steel X5CrNi18-10 (1.4301). As a metastable austenitic steel which can initiate cutting impact on the press through martensitization, fine blanking of stainless steel is a challenge. X5CrNi18-10 is not a high-strength steel per se but becomes difficult to process due to the high hardness of the martensite phase, known as transformation-induced plasticity (TRIP) effect. Thus, in order to combine the possible advantages of the fine blanking process with inductive heating and the important properties of stainless steel, fine blanking of this steel was investigated with inductive heating prior to the fine blanking. The process forces and product quality properties such as die roll were investigated and found to be advantageous in comparison to non-heated fine blanking specimens of the same steel. The process forces and the die roll height decreased due to the heating.

Application of Fine Blanking to the Manufacture of a Sprocket with Stainless Steel Sheet

2004 ◽  
Vol 261-263 ◽  
pp. 1665-1670 ◽  
Author(s):  
Y.H. Seo ◽  
Byoung Kee Kim ◽  
H.D. Son
Keyword(s):  
Stainless Steel ◽  
Unit Cost ◽  
Damage Model ◽  
Hardness Test ◽  
Simple Method ◽  
Fine Blanking ◽  
3 Dimensional ◽  
Deform 2D ◽  
Die Roll ◽  
Blanking Process

Wire cutting(EDM) or blanking is used to made workpieces from sheet metal. Wire EDM provides a relatively simple method for making holes of any desired cross section in material. But EDM requires a lot of working time and the high unit cost of production. In conventional blanking, for the production of precision devices or assemblies, it is always necessary that at least two, but generally more, secondary operations are required per piece part. Using the fine blanking process, a precise finished part with inner and outer forms clearly sheared over the whole material thickness are produced in one single operation. In this study an attempt is made to manufacture a sprocket with fine blanking process. The sprocket is parts for the tape feeder of surface mount system in electronic parts. First, a change of the existing design is made in a sprocket. The materials selected are three kinds of stainless steel, SUS304, SUS316 and SUS430. And the mechanical properties are investigated through the tensile test. After fine blanking, hardness and precision are examined with hardness test and 3-dimensional coordinate measuring for samples. The results of investigations of fine-blanking process with the help of FEM code, DEFORM 2D, are presented. For the simulation, SUS304 and SUS316 are used as materials. The damage model of Cockroft and Latham is used to calculate damage. Die-roll height, die-roll width, burnish zone and fracture zone from the fine blanking simulation are investigated in comparison with them of samples. And the applied force at each part of fine-blanking die is estimated with load-stroke diagram.

Use of Duplex Stainless Steel in Economic Design of a Pressure Vessel

2006 ◽  
Vol 129 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Milan Veljkovic ◽  
Jonas Gozzi
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Pressure Vessel ◽  
Design Procedure ◽  
High Strength Steels ◽  
High Strength ◽  
Pressure Vessels ◽  
Economic Design ◽  
European Standard

Pressure vessels have been used for a long time in various applications in oil, chemical, nuclear, and power industries. Although high-strength steels have been available in the last three decades, there are still some provisions in design codes that preclude a full exploitation of its properties. This was recognized by the European Equipment Industry and an initiative to improve economy and safe use of high-strength steels in the pressure vessel design was expressed in the evaluation report (Szusdziara, S., and McAllista, S., EPERC Report No. (97)005, Nov. 11, 1997). Duplex stainless steel (DSS) has a mixed structure which consists of ferrite and austenite stainless steels, with austenite between 40% and 60%. The current version of the European standard for unfired pressure vessels EN 13445:2002 contains an innovative design procedure based on Finite Element Analysis (FEA), called Design by Analysis-Direct Route (DBA-DR). According to EN 13445:2002 duplex stainless steels should be designed as a ferritic stainless steels. Such statement seems to penalize the DSS grades for the use in unfired pressure vessels (Bocquet, P., and Hukelmann, F., 2001, EPERC Bulletin, No. 5). The aim of this paper is to present an investigation performed by Luleå University of Technology within the ECOPRESS project (2000-2003) (http://www.ecopress.org), indicating possibilities towards economic design of pressure vessels made of the EN 1.4462, designation according to the European standard EN 10088-1 Stainless steels. The results show that FEA with von Mises yield criterion and isotropic hardening describe the material behaviour with a good agreement compared to tests and that 5% principal strain limit is too low and 12% is more appropriate.

The effects of tool geometry change on shearing edge finish in fine-blanking of different materials

2003 ◽  
Vol 217 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
Y C Leung ◽  
L C Chan ◽  
C H Cheng ◽  
T C Lee
Keyword(s):  
Tool Geometry ◽  
Nose Radius ◽  
Fine Blanking ◽  
Burr Height ◽  
Service Period ◽  
Edge Surface ◽  
Edge Quality ◽  
Processing Material ◽  
Die Roll ◽  
Blanking Process

An excellent quality of shearing edge implies that a smooth cutting edge without tearing will be observed on the whole edge surface. This is one of the most significant features of the fine-blanking process. To achieve this good blanking edge quality in fine-blanking, quite a large number of factors need to be considered simultaneously during the operation, such as blanking speed, processing material, product shape, lubrication and tool geometry. Thus, the objective of this paper is mainly to study the influence of tool geometry change in fine-blanking for different materials. This is because the nose radius usually seriously deteriorates with increasing service period in mass production, which eventually causes the entire loss of the specific features of the fine-blanking process. Therefore, a tailor-made experimental study was carried out to investigate the relationship between the punch nose radius and the shearing edge quality, such as the shearing edge surface finish, burr height and die-roll height, during fine-blanking for different types of materials. Consequently, findings show that an increase in the punch nose radius produces a higher percentage of fracture of the blanked edge and increases the amount of burr height.

scholarly journals A Novel Force Variation Fine Blanking Process for the High-strength and Low-plasticity Material

2021 ◽  
Author(s):  
Huajie Mao ◽  
Han Chen ◽  
Yanxiong Liu ◽  
Kaisheng Ji
Keyword(s):  
Early Stage ◽  
Hydrostatic Stress ◽  
High Strength ◽  
Forming Force ◽  
Forming Process ◽  
Fine Blanking ◽  
Application Range ◽  
Cutting Surface ◽  
Force Variation ◽  
Blanking Process

Abstract Fine blanking is a kind of metal forming process with the advantages of high precision, good surface quality and low cost. Influenced by the concept of lightweight, a large number of metal materials with high strength are widely used in various fields. High strength materials are prone to be cracked during plastic deformation due to their poor plasticity, which limits the application range of them. This paper proposed a force variation fine blanking process for high-strength and low-plasticity materials. At the same time, a method to find the curve of forming force for this novel process was presented. A 2D finite element fine blanking model was established for the TC4 material. Combining genetic algorithm and neural network methods, a model was built up to find the optimal forming force loading curve. The parts fabricated by force variation loading and constant loading fine blanking process were compared through experiments. The mechanism of force variation fine blanking is also revealed. The forming force mainly affects the length of clean cutting surface by affecting hydrostatic stress. According to the ultimate optimal loading curve, the forming force should be kept at a low level in the early stage of blanking stroke, and increased gradually in the ending stage. In the application of force variation fine blanking, the part with long length of clean cutting surface can be obtained with lower die load.

scholarly journals Interface Characteristics and Properties of a High-Strength Corrosion-Resistant Stainless Steel Clad Rebar

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 373
Author(s):  
Xuming Liu ◽  
Guanghong Feng ◽  
Xin Liu ◽  
Baoshan Wang ◽  
Hongliang Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Transition Zone ◽  
High Strength ◽  
Martensite Phase ◽  
Duplex Structure ◽  
Bending Tests ◽  
Metallurgical Bonding ◽  
Interface Characteristics ◽  
Rolling Method ◽  
Negative Bending

This paper aims at manufacturing stainless steel clad (SSC) rebars by metal deposition and a hot rolling method as well as characterizing its interface features and mechanical properties. The interface of the SSC rebar is relatively flat and clean, exhibiting a metallurgical bonding state at the microscale. Decarburization occurred at the interface in the carbon steel side of the SSC rebar. The diffusion of C, Cr, as well as Mn was measured across the interface of the SSC rebar, and the diffusion distance of Cr and Mn was found at 32 µm and 25 µm, respectively. The Vickers hardness testing in the transition zone of the SSC rebar near the carbon side showed 545 HV0.2 due to the martensite phase formed by the diffusion of key elements C, Cr, and Mn. The microstructure in the transition zone near the stainless steel reveals the duplex structure of martensite and ferrite. The carbide precipitations were observed near the interface, both in the transition zone and in the base metal of the stainless steel zone. The yield strength, tensile strength, and elongation of the SSC rebar were found as 423 MPa, 602 MPa, and 22%. No macroscopic crack was observed after the positive or negative bending tests.

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