Metal Cutting - PowerPoint PPT Presentation

Loading...

PPT – Metal Cutting PowerPoint presentation | free to download - id: 3ef17e-M2EyN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Metal Cutting

Description:

Metal Cutting Plasma Oxy Fuel Plasma Arc Cutting (PAC) is a cutting process that uses an arc and a high-velocity, ionized gas coming through a nozzle to cut all ... – PowerPoint PPT presentation

Number of Views:146
Avg rating:3.0/5.0
Slides: 21
Provided by: BREN107
Category:
Tags: cutting | metal | welding

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Metal Cutting


1
Metal Cutting
  • Plasma
  • Oxy Fuel

2
Plasma Arc Cutting (PAC)
  • is a cutting process that uses an arc and a
    high-velocity, ionized gas coming through a
    nozzle to cut all metals that can not be cut with
    flame
  • Such as
  • Stainless steel
  • Aluminum
  • Copper

3
PAC
  • Plasma is a super heated gas that is ionized.
  • Ionized- Electrons in the gas have broken away
    form their atoms and will conduct electricity.
  • Gases used for plasma cutting includes
  • Hydrogen
  • Argon
  • Nitrogen and mixture ,plus air and oxygen

4
PAC
  • How it cuts
  • The plasma gas (compressed air) is forced through
    a nozzle and heated by the arc which reaches to
    5,0000F

5
Advantages of PAC
  • Can cut all metals
  • Fast cutting speeds
  • Little distortion from heat
  • No hazardous gases
  • Oxygen based system do not leave nitride deposits
  • Nitrogen based systems are for aluminum,
    stainless steel and nickel

6
Disadvantages
  • Plasma Torch is expensive
  • Not portable (needs electricity)
  • Metal fumes created can be a health hazard
  • Puts tremendous heat into the metal around the
    cut
  • Creates HAZ
  • Hardens materials next to the cut

7
Safety/ Maintenance
  • A minimum of a 9 filter shield should be used
  • Need proper ventilation to remove harmful gases
  • Dip electrode into anti-spatter compound
  • Do not allow Pilot Arc to continue for long
    periods of time

8
Setting the PAC TorchIf torch amps is set too
high travel speed needs to be increased
Thickness Current Travel Speed
1/16 35 amps 175 in/min
1/8 40 amps 90 in/min
1/4 40 amps 40 in/min
1/4 80 amps 100 in/min
3/8 40 amps 18 in/min
3/8 80 amps 55 in/min
1/2 40 amps 20 in/min
1/2 80 amps 35 in/min
9
How to Use
  • Clean metal
  • Hook up ground cable
  • Draw cutting pattern on metal
  • Hold torch 1/16-1/8 from metal (torch stand will
    help maintain this)
  • Hold torch at a 70 to 90 angle
  • Pull button when arc begins pull torch across
    metal

10
Cutting Speed
  • Too Slow- Molten metal will collect on bottom of
    work piece and need to be ground off (this is
    called Dross)
  • Too Fast- Metal will not be cut all the way
    through

11
Oxy-Fuel Cutting
12
Oxy-Fuel Cutting, Welding
  • Definition
  • Burning is the rapid oxidation of a material
  • Does Metal Burn?
  • Virtually all materials will burn if they are
    first heated to their ignition temperature.
  • Steel ignition temp is when it is cherry red,
    1300-1400 C
  • Oxygen burns preheated metal and blows it away
    from the work piece.

13
  • Oxyacetylene welding (OAW)
  • Oxygen and acetylene gas are mixed in the
    torch tip. The mixture burns at the torch tip.
  • The heat from this flame is used to melt the
    base metal and welding rod. This melted material
    forms a weld joint.

14
OFC Equipment
Combination Cutting Torch with Cutting Attachment
Straight Cutting Torch
15
Cutting Tips
3690 Cutting Tip
3690-P Cutting Tip
16
OFC Cutting Tip Information
17
Oxy-Fuel Cutting Set-up
  • All set up the same as oxy-fuel welding except
  • To set working pressure for oxygen must open
    cutting valve

18
Oxy-Fuel Cutting Process
  • Clean metal
  • Draw line
  • Make jig to keep cut straight
  • Hold tip 1/16-1/8 above metal
  • Preheat metal to cherry red color
  • Open oxygen valve and push torch through metal
  • (Angle tip slightly toward direction of cut)

19
Cutting Flame Types
Carburizing Flame
Neutral Flame
Neutral Flame with Oxygen Cutting Stream
Oxidizing Flame
20
Advantages
  • Can cut complex shape
  • Can cut carbon and low carbon steel
  • Inexpensive process
  • Can have multiple cutting torch
  • Disadvantages
  • It is slower than other cutting systems
  • Cut accuracy is not as good as plasma, water jet
    ,laser
  • Creates heat affected zone
About PowerShow.com