Title of Invention	A METHOD FOR ON-LINE PREDICTION OF NECKING AND RUPTURE FAILURE DURING SHEET METAL FORMING PROCESS BY ADAPTING MULTIPLE SIMULATION
Abstract	The invention relates to a method for on-line determination of onset of necking and rupture failure during sheet metal forming process by adapting multiple simulation, the method comprising the steps of designing a virtual tool (1) and a cross-die (2) corresponding to actual geometrical shape of a sheet metal (3) to be formed; collecting data in respect of shape, size and thickness of the formable sheet metal (3); determining the working condition being one of hot and cold; recording data for tool travel during stamping; recording load requirement for stamping; recording a load at which a first failure occurs in a trial operation; recording percentage strain in maximum principal strain direction at the end of the full stroke of the tool; recording the strain values in minor principal strain direction at each time step of the tool travel for the sheet metal particles; plotting a graph with values of minor principal strain direction (y-axis) vs termination time (x-axis). A value of slope change from the plotted graph is recorded ; and in that the time which provides the onset of necking and rupture failure occurrence corresponding to the slope change point is selected.

Title of Invention

A METHOD FOR ON-LINE PREDICTION OF NECKING AND RUPTURE FAILURE DURING SHEET METAL FORMING PROCESS BY ADAPTING MULTIPLE SIMULATION

Abstract

The invention relates to a method for on-line determination of onset of necking and rupture failure during sheet metal forming process by adapting multiple simulation, the method comprising the steps of designing a virtual tool (1) and a cross-die (2) corresponding to actual geometrical shape of a sheet metal (3) to be formed; collecting data in respect of shape, size and thickness of the formable sheet metal (3); determining the working condition being one of hot and cold; recording data for tool travel during stamping; recording load requirement for stamping; recording a load at which a first failure occurs in a trial operation; recording percentage strain in maximum principal strain direction at the end of the full stroke of the tool; recording the strain values in minor principal strain direction at each time step of the tool travel for the sheet metal particles; plotting a graph with values of minor principal strain direction (y-axis) vs termination time (x-axis). A value of slope change from the plotted graph is recorded ; and in that the time which provides the onset of necking and rupture failure occurrence corresponding to the slope change point is selected.

Full Text	FIELD OF THE INVENTION The present invention relates to a method for predicting necking and rupture failure occurrence during sheet metal formability process. More particularly, the present invention relates to a method for on line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation. BACKGROUND OF THE INVENTION Various methods are known for forming a metal sheet. One method involves a draw process wherein a tool pulls a portion of the metal sheet through a shaped die. During the process, the metal sheet typically undergoes a reduction or change in the cross-sectional area or wall thickness of the sheet. Such processes are typically limited by the material's ability to be strained past its rupture point. Thus, depending upon the complexity of the part, the forming stresses on the metal sheet during the forming process may result in metal failure or fatigue and correspondingly an unusable or scrap part. Superplastic forming (SPF) is a process that takes advantage of a material's superplasticity or ability to be strained past its rupture point under certain elevated temperature conditions. Superplasticity in metals is defined by very high tensile elongation and is the ability of certain materials to undergo extreme elongation at proper temperature and strain rate. SPF is a process used to produce parts that are difficult to form using conventional fabrication techniques. During the superplastic forming process, the metal sheet, or as often referred to the blank, is heated to a point of superplasticity after which a predefined gas pressure is applied to one side of the sheet. The pressure forces the sheet into a die cavity while maintaining a target strain rate for deforming the sheet throughout the forming cycle. The superplasticity of the material enables forming of complex components that normally cannot be formed by conventional room temperature metal forming processes. Use of a superplastic forming process enables forming a workpiece with a deep cavity or one formed over very small radii. Superplastic forming does have a disadvantage in that it normally requires relatively long forming cycle times. Specifically, a conventional SPF process used to manufacture a complex part can require a forming cycle time as high as 30 minutes. Further, superplastic forming cannot always be used to obtain a complex part in a single step and therefore may require two or more forming steps. U.S. Pat. No. 6,581,428 illustrates one method for forming a part that uses a single die capable of preforming both a mechanical draw process and superplastic forming process. The '428 patent utilizes a pre-forming punch disposed on one of the die members, wherein the punch pre-forms the blank prior to an application of gas pressure to the blank to complete the forming process. While this die structure and corresponding process is well suited to many applications, the die structure is somewhat complex and may not accommodate forming some aspects of a complex part such as small radii and corners without causing wrinkling during the drawing process. The primary mode of failure in sheet metal forming is the onset of local plastic instability or a localized neck. Neck grows from the initial geometric or material inhomogeneity. Flow localization during sheet stretching limits metal formability. Sheet metal necks fail in locations where critical limit strains are exceeded. During stamping, a sheet is subjected to a very complex deformation history and boundary conditions. Finite element simulation of the sheet metal forming process has been developed to minimize the time and cost in the design phase by predicting key outcomes such as the final shape of the part, the possibility of various defects and the flow material. The usefulness of numerical simulation in designing sheet metal forming processes requires precise criteria to identify the modes of failure such as tearing, wrinkling or geometry deviation due to springbcak. Also, simulation analysis needs an experimental forming limit curve of the respective sheet metal, which is a difficult and a time consuming task. The risk failure is normally evaluated by the post-processing of the results from the simulation codes, but the Forming Limit Diagram (FLD) should also be built in the material model as a failure criteria. The strains obtained during forming will be incorporated in the Forming Limit Diagram to know whether strains are within safe limits or not, so that modification in material, process parameters can be incorporated to get successful stampings. But it is difficult to know the limit without the FLD. OBJECTS OF THE INVENTION It is therefore an object of the present invention to propose a method for on-line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation which eliminates the existing working failure during production. Another object of the present invention is to propose a method for on-line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation which enables outputting of improved finished product during the production process. A further object of the present invention is to propose a method for on-line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation which saves cost and time and allow to run the system economically. A still another object of the present invention is to propose a method for on-line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation which reduces the rejection percentage. SUMMARY OF THE INVENTION Accordingly, there is provided a method for on-line prediction of necking and rupture failure during sheet metal forming process by adapting multiple simulation, the method comprising the steps of: designing a tool and a cross-die corresponding to actual geometrical shape of the sheet metal to be formed; collecting data in respect of shape, size and thickness of the formable sheet metal; determining the working condition being one of hot and cold; recording data for tool travel during the step of stamping; recording a load requirement in a trial mode for stamping; recording a load at which a first failure occurs during the trial operation; recording respectively the percentage strain value in terms of maximum principal strain direction including the percentage strain value in terms of minor principal strain directions at the end of a full stroke of the tool and at each time step for the particles; plotting a graph with values of minor principal strain (y-axis) vs termination time (x-axis); recording the value of the slope change from the plotted graph; and selecting the time which indicates the onset of necking occurrence corresponding to the slope change point. After collecting all the numerical data, a numerical simulation is implemented adapting an incremental software in a computer apparatus. The full punch travel of the tool and the corresponding to the simulated termination time is calculated. The data of punch (tool) travel distance is plotted in X-axis (corresponding to the simulation termination time in milliseconds) and the minor strains (%) in Y-axis that inturn yield a slope change corresponding to time which matches with the time at which the particles start crossing the FLD (Forming Limit Diagram). A selection of optimum strain region is made by discarding the other regions to prevent necking and rupture failure. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 - Schematically shows a virtual Tool geometry including a cross-die. Figure 2 - Shows the geometry of the deformed steel sheet. Figure 3 - Graphically illustrates the strain states of the particles of the steel sheet at stroke 24 of the tool. Figure 4 - Graphically represents a relationship between minor strain and time indicating a slope change. Figure 5 - Graphically shows a relationship between strains and time with indication of time the particles cross the FLD. BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Figure 1 shows a virtual tool (1) and a formable sheet metal (3), including a cross Die (2). The tool (1) can travel freely into the lower die (2) during stamping (punching) operation. The steel sheet (3) is placed in between the tool (1) and a cavity (4) of the die (2) for operation of the sheet metal forming process. Figure 2 shows the final deformed sheet after stamping operation having a contour corresponding to the configuration of the die cavity (4) at the end of a full punch stroke. Figure 3 shows the strain states of the particles of the steel sheet (3) at stroke 24 mm where some particles (5) cross the Forming Limit Curve (6). From figure 3, it is clear that necking and rupture occurrence starts at stroke 24 mm. A numerical simulation has been carried out for the full punch stroke. For the full punch stroke, a corresponding simulation time for termination (7) is found to be 6.4 milliseconds. Total punch travel distance has been divided into 10 steps. So will be clear that, rupture occurrence (8) at 2.4 milliseconds is predicted from the criteria developed. From the simulation results, a new method has been developed as under: 1. running the simulation for minimum ten time steps, 2. noting the particles having the maximum principal strain at the end of the full stroke, 3. determining the minor principal strain values at each time step for that particles, 4. if the particles are form-adaptive mesh, determining the minor principal strain values from where the adaptive meshing starts for that element, 5. plotting a graph between the minor principal strain and the termination time, 6. noting the slope change from the graph plotted, 7. The time, which indicates the onset of necking occurrence, is the time corresponding to the slope change point of the immediate next to the slope change point. By applying the new criteria and the steps as mentioned above, figure 4 has been plotted between the punch travel distance (corresponding simulation termination time in milliseconds) in the x-axis and the minor strains (%) the y- axis. Figure 4 gives the slope change time between 2.4 to 3 millisecond, which is matching with the time at which particles crossing Forming Limit Diagram. As mentioned hereinabove, simulation has been carried out for stamping of outer panel to verify the criteria applicable to the adaptive mesh elements. Figure 5 shows the time at which the particles of the sheet metal cross the FLD. By comparing the forming strains with Forming Limit Diagram at the end of each step, it shows that particles starts to cross (9) the forming limit diagram at a time of 43.11 milliseconds. Since the adaptive meshing starts at 40 milliseconds, the strain values are noted from 40 milliseconds upto the end of stroke, which (10) is 46 milliseconds. Thus, the slope changing time is 43.11 milliseconds, which corresponds to the stroke at rupture for the outer panel of the sheet. Detailed analysis has been carried out and verified from the simulation result of both the cross die (2) and the outer panel of the sheet (3) using the criteria developed to predict the necking and rupture occurrence. WE CLAIM 1. A method for on-line determination of onset of necking and rupture failure during sheet metal forming process by adapting multiple simulation, the method comprising the steps of: - designing a virtual tool (1) and a cross-die (2) corresponding to actual geometrical shape of a sheet metal (3) to be formed; - collecting data in respect of shape, size and thickness of the formable sheet metal (3); - determining the working condition being one of hot and cold; - recording data for tool travel during stamping; - recording load requirement for stamping; - recording a load at which a first failure occurs in a trial operation; - recording percentage strain in maximum principal strain direction at the end of the full stroke of the tool; - recording the strain values in minor principal strain direction at each time step of the tool travel for the sheet metal particles; - plotting a graph with values of minor principal strain direction (y-axis) vs termination time (x-axis); characterized in that : a value of slope change from the plotted graph is recorded ; and in that the time which provides the onset of necking and rupture failure occurrence corresponding to the slope change point is selected. 2. A method for on-line determination of onset of the necking and rupture failure during sheet metal forming process by adapting multiple simulation as substantially herein described with reference to the accompanying drawings. The invention relates to a method for on-line determination of onset of necking and rupture failure during sheet metal forming process by adapting multiple simulation, the method comprising the steps of designing a virtual tool (1) and a cross-die (2) corresponding to actual geometrical shape of a sheet metal (3) to be formed; collecting data in respect of shape, size and thickness of the formable sheet metal (3); determining the working condition being one of hot and cold; recording data for tool travel during stamping; recording load requirement for stamping; recording a load at which a first failure occurs in a trial operation; recording percentage strain in maximum principal strain direction at the end of the full stroke of the tool; recording the strain values in minor principal strain direction at each time step of the tool travel for the sheet metal particles; plotting a graph with values of minor principal strain direction (y-axis) vs termination time (x-axis). A value of slope change from the plotted graph is recorded ; and in that the time which provides the onset of necking and rupture failure occurrence corresponding to the slope change point is selected.

Full Text

FIELD OF THE INVENTION
The present invention relates to a method for predicting necking and rupture
failure occurrence during sheet metal formability process. More particularly, the
present invention relates to a method for on line prediction of necking and
rupture failure during sheet metal forming process by adapting multiple
simulation.
BACKGROUND OF THE INVENTION
Various methods are known for forming a metal sheet. One method involves a
draw process wherein a tool pulls a portion of the metal sheet through a shaped
die. During the process, the metal sheet typically undergoes a reduction or
change in the cross-sectional area or wall thickness of the sheet. Such processes
are typically limited by the material's ability to be strained past its rupture point.
Thus, depending upon the complexity of the part, the forming stresses on the
metal sheet during the forming process may result in metal failure or fatigue and
correspondingly an unusable or scrap part.
Superplastic forming (SPF) is a process that takes advantage of a material's
superplasticity or ability to be strained past its rupture point under certain
elevated temperature conditions. Superplasticity in metals is defined by very high
tensile elongation and is the ability of certain materials to undergo extreme
elongation at proper temperature and strain rate. SPF is a process used to
produce parts that are difficult to form using conventional fabrication techniques.

During the superplastic forming process, the metal sheet, or as often referred to
the blank, is heated to a point of superplasticity after which a predefined gas
pressure is applied to one side of the sheet. The pressure forces the sheet into a
die cavity while maintaining a target strain rate for deforming the sheet
throughout the forming cycle. The superplasticity of the material enables forming
of complex components that normally cannot be formed by conventional room
temperature metal forming processes. Use of a superplastic forming process
enables forming a workpiece with a deep cavity or one formed over very small
radii. Superplastic forming does have a disadvantage in that it normally requires
relatively long forming cycle times. Specifically, a conventional SPF process used
to manufacture a complex part can require a forming cycle time as high as 30
minutes.
Further, superplastic forming cannot always be used to obtain a complex part in
a single step and therefore may require two or more forming steps. U.S. Pat. No.
6,581,428 illustrates one method for forming a part that uses a single die
capable of preforming both a mechanical draw process and superplastic forming
process. The '428 patent utilizes a pre-forming punch disposed on one of the die
members, wherein the punch pre-forms the blank prior to an application of gas
pressure to the blank to complete the forming process. While this die structure
and corresponding process is well suited to many applications, the die structure
is somewhat complex and may not accommodate forming some aspects of a
complex part such as small radii and corners without causing wrinkling during
the drawing process.

The primary mode of failure in sheet metal forming is the onset of local plastic
instability or a localized neck. Neck grows from the initial geometric or material
inhomogeneity. Flow localization during sheet stretching limits metal formability.
Sheet metal necks fail in locations where critical limit strains are exceeded.
During stamping, a sheet is subjected to a very complex deformation history and
boundary conditions. Finite element simulation of the sheet metal forming
process has been developed to minimize the time and cost in the design phase
by predicting key outcomes such as the final shape of the part, the possibility of
various defects and the flow material. The usefulness of numerical simulation in
designing sheet metal forming processes requires precise criteria to identify the
modes of failure such as tearing, wrinkling or geometry deviation due to
springbcak. Also, simulation analysis needs an experimental forming limit curve
of the respective sheet metal, which is a difficult and a time consuming task. The
risk failure is normally evaluated by the post-processing of the results from the
simulation codes, but the Forming Limit Diagram (FLD) should also be built in the
material model as a failure criteria. The strains obtained during forming will be
incorporated in the Forming Limit Diagram to know whether strains are within
safe limits or not, so that modification in material, process parameters can be
incorporated to get successful stampings. But it is difficult to know the limit
without the FLD.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a method for on-line
prediction of necking and rupture failure during sheet metal forming process by

adapting multiple simulation which eliminates the existing working failure during
production.
Another object of the present invention is to propose a method for on-line
prediction of necking and rupture failure during sheet metal forming process by
adapting multiple simulation which enables outputting of improved finished
product during the production process.
A further object of the present invention is to propose a method for on-line
prediction of necking and rupture failure during sheet metal forming process by
adapting multiple simulation which saves cost and time and allow to run the
system economically.
A still another object of the present invention is to propose a method for on-line
prediction of necking and rupture failure during sheet metal forming process by
adapting multiple simulation which reduces the rejection percentage.
SUMMARY OF THE INVENTION
Accordingly, there is provided a method for on-line prediction of necking and
rupture failure during sheet metal forming process by adapting multiple
simulation, the method comprising the steps of: designing a tool and a cross-die
corresponding to actual geometrical shape of the sheet metal to be formed;
collecting data in respect of shape, size and thickness of the formable sheet
metal; determining the working condition being one of hot and cold; recording

data for tool travel during the step of stamping; recording a load requirement in
a trial mode for stamping; recording a load at which a first failure occurs during
the trial operation; recording respectively the percentage strain value in terms of
maximum principal strain direction including the percentage strain value in terms
of minor principal strain directions at the end of a full stroke of the tool and at
each time step for the particles; plotting a graph with values of minor principal
strain (y-axis) vs termination time (x-axis); recording the value of the slope
change from the plotted graph; and selecting the time which indicates the onset
of necking occurrence corresponding to the slope change point.
After collecting all the numerical data, a numerical simulation is implemented
adapting an incremental software in a computer apparatus. The full punch travel
of the tool and the corresponding to the simulated termination time is calculated.
The data of punch (tool) travel distance is plotted in X-axis (corresponding to the
simulation termination time in milliseconds) and the minor strains (%) in Y-axis
that inturn yield a slope change corresponding to time which matches with the
time at which the particles start crossing the FLD (Forming Limit Diagram). A
selection of optimum strain region is made by discarding the other regions to
prevent necking and rupture failure.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - Schematically shows a virtual Tool geometry including a cross-die.
Figure 2 - Shows the geometry of the deformed steel sheet.

Figure 3 - Graphically illustrates the strain states of the particles of the steel
sheet at stroke 24 of the tool.
Figure 4 - Graphically represents a relationship between minor strain and time
indicating a slope change.
Figure 5 - Graphically shows a relationship between strains and time with
indication of time the particles cross the FLD.
BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Figure 1 shows a virtual tool (1) and a formable sheet metal (3), including a
cross Die (2). The tool (1) can travel freely into the lower die (2) during
stamping (punching) operation. The steel sheet (3) is placed in between the tool
(1) and a cavity (4) of the die (2) for operation of the sheet metal forming
process.
Figure 2 shows the final deformed sheet after stamping operation having a
contour corresponding to the configuration of the die cavity (4) at the end of a
full punch stroke.
Figure 3 shows the strain states of the particles of the steel sheet (3) at stroke
24 mm where some particles (5) cross the Forming Limit Curve (6). From figure
3, it is clear that necking and rupture occurrence starts at stroke 24 mm. A
numerical simulation has been carried out for the full punch stroke. For the full
punch stroke, a corresponding simulation time for termination (7) is found to be

6.4 milliseconds. Total punch travel distance has been divided into 10 steps. So
will be clear that, rupture occurrence (8) at 2.4 milliseconds is predicted from the
criteria developed. From the simulation results, a new method has been
developed as under:
1. running the simulation for minimum ten time steps,
2. noting the particles having the maximum principal strain at the end of the
full stroke,
3. determining the minor principal strain values at each time step for that
particles,
4. if the particles are form-adaptive mesh, determining the minor principal
strain values from where the adaptive meshing starts for that element,
5. plotting a graph between the minor principal strain and the termination
time,
6. noting the slope change from the graph plotted,
7. The time, which indicates the onset of necking occurrence, is the time
corresponding to the slope change point of the immediate next to the
slope change point.

By applying the new criteria and the steps as mentioned above, figure 4 has
been plotted between the punch travel distance (corresponding simulation
termination time in milliseconds) in the x-axis and the minor strains (%) the y-
axis. Figure 4 gives the slope change time between 2.4 to 3 millisecond, which is
matching with the time at which particles crossing Forming Limit Diagram.
As mentioned hereinabove, simulation has been carried out for stamping of outer
panel to verify the criteria applicable to the adaptive mesh elements. Figure 5
shows the time at which the particles of the sheet metal cross the FLD. By
comparing the forming strains with Forming Limit Diagram at the end of each
step, it shows that particles starts to cross (9) the forming limit diagram at a
time of 43.11 milliseconds. Since the adaptive meshing starts at 40 milliseconds,
the strain values are noted from 40 milliseconds upto the end of stroke, which
(10) is 46 milliseconds. Thus, the slope changing time is 43.11 milliseconds,
which corresponds to the stroke at rupture for the outer panel of the sheet.
Detailed analysis has been carried out and verified from the simulation result of
both the cross die (2) and the outer panel of the sheet (3) using the criteria
developed to predict the necking and rupture occurrence.

WE CLAIM
1. A method for on-line determination of onset of necking and rupture failure
during sheet metal forming process by adapting multiple simulation, the
method comprising the steps of:
- designing a virtual tool (1) and a cross-die (2) corresponding to actual
geometrical shape of a sheet metal (3) to be formed;
- collecting data in respect of shape, size and thickness of the formable sheet
metal (3);
- determining the working condition being one of hot and cold;
- recording data for tool travel during stamping;
- recording load requirement for stamping;
- recording a load at which a first failure occurs in a trial operation;
- recording percentage strain in maximum principal strain direction at the end
of the full stroke of the tool;
- recording the strain values in minor principal strain direction at each time
step of the tool travel for the sheet metal particles;

- plotting a graph with values of minor principal strain direction (y-axis) vs
termination time (x-axis); characterized in that :
a value of slope change from the plotted graph is recorded ; and in that
the time which provides the onset of necking and rupture failure occurrence
corresponding to the slope change point is selected.
2. A method for on-line determination of onset of the necking and rupture
failure during sheet metal forming process by adapting multiple simulation as
substantially herein described with reference to the accompanying drawings.

The invention relates to a method for on-line determination of onset of necking
and rupture failure during sheet metal forming process by adapting multiple
simulation, the method comprising the steps of designing a virtual tool (1) and a
cross-die (2) corresponding to actual geometrical shape of a sheet metal (3) to
be formed; collecting data in respect of shape, size and thickness of the formable
sheet metal (3); determining the working condition being one of hot and cold;
recording data for tool travel during stamping; recording load requirement for
stamping; recording a load at which a first failure occurs in a trial operation;
recording percentage strain in maximum principal strain direction at the end of
the full stroke of the tool; recording the strain values in minor principal strain
direction at each time step of the tool travel for the sheet metal particles;
plotting a graph with values of minor principal strain direction (y-axis) vs
termination time (x-axis). A value of slope change from the plotted graph is
recorded ; and in that the time which provides the onset of necking and rupture
failure occurrence corresponding to the slope change point is selected.

Documents:

01026-kol-2006-abstract.pdf

01026-kol-2006-correspondence-1.1.pdf

01026-kol-2006-form-9.pdf

01026-kol-2006.claims.pdf

01026-kol-2006.correspondence others.pdf

01026-kol-2006.description(complete).pdf

01026-kol-2006.drawings.pdf

01026-kol-2006.form-1.pdf

01026-kol-2006.form-2.pdf

01026-kol-2006.form-3.pdf

01026-kol-2006.g.p.a.pdf

1026 KOL 2006 Search Report.pdf

1026-KOL-2006-(29-05-2012)-CORRESPONDENCE.pdf

1026-KOL-2006-AMANDED CLAIMS.pdf

1026-KOL-2006-CORRESPONDENCE.pdf

1026-KOL-2006-CORRESPONDENCE1.1.pdf

1026-KOL-2006-EXAMINATION REPORT.pdf

1026-KOL-2006-FORM 13.1.pdf

1026-kol-2006-form 13.pdf

1026-KOL-2006-FORM 18.pdf

1026-KOL-2006-FORM 3.pdf

1026-KOL-2006-FORM 9.pdf

1026-KOL-2006-GPA.pdf

1026-KOL-2006-GRANTED-ABSTRACT.pdf

1026-KOL-2006-GRANTED-CLAIMS.pdf

1026-KOL-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

1026-KOL-2006-GRANTED-DRAWINGS.pdf

1026-KOL-2006-GRANTED-FORM 1.pdf

1026-KOL-2006-GRANTED-FORM 2.pdf

1026-KOL-2006-GRANTED-SPECIFICATION.pdf

1026-KOL-2006-OTHERS.pdf

1026-KOL-2006-REPLY TO EXAMINATION REPORT.pdf

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Patent Number

253037

Indian Patent Application Number

1026/KOL/2006

PG Journal Number

25/2012

Publication Date

22-Jun-2012

Grant Date

19-Jun-2012

Date of Filing

05-Oct-2006

Name of Patentee

TATA STEEL LIMITED

Applicant Address

JAMSHEPUR 831 001, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	P. SARAVANAN	TATA STEEL LIMITED JAMSHEDPUR 831 001, INDIA

PCT International Classification Number

G06F17/50

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA