Metal Heat Treatment. Processes Equipment Controls. Retrofits. Service. iTools. Barber-Colman/Eurotherm Thermal Solutions. Sensors. Actuators. Multi-Loop Controllers. Single Loop Controllers. THE HEAT TREATING PROCESS. Heat treated components are essential to the operation of…
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Requires three basic steps:
Grades of Steel Typically Heat Treated
1000, 1100, 1200, 1300, 1500
4000, 4100, 4600, 5100, 6100
8600, 9300 series
1040 = .37 to .44 carbon content
Standard carbon steel
8620 = .18 to .23 carbon content
Carburizing grade alloy steel
1 hour .62C .012”
4 hours .71C .026”
20 hours .86C .061”
Simple Boost and Diffuse
fuel-gas air mixture combustion burns directly into heating chamber material may be protected from oxidation and/or products of combustion by passing through a MUFFLE or RETORT.
fuel-gas air mixture combustion circulates inside radiant tubes. Heat is radiated through the tube walls into the heating chamber. Radiant tubes are nickel alloy, ceramic or occasionally silicon carbide
exposed - open to heating chamber environment
indirect - isolated from chamber by insertion into radiant tube(s)
elements are typically Ni - Cr alloy in wire, rod, ribbon or sheetmetal form
NEW FURNACE HARDWARE TECHNOLOGY
.40%C = 400F D.P.
.60%C = 280F
.80%C = 200F
1.00%C = 130F
.30%C = 660F D.P.
.50%C = 500F D.P.
.70%C = 400F D.P.
The actual oxygen content in a typical carburizing atmosphere is 1 billionth of 1 billionth of one percent.
Atmosphere at 40oF DP provides different %C at different temperatures.
Example: 1500oF = .75%C
1600oF = .60%C
1700oF = .40%C
For carbon potential above saturation sooting will occur and non-controlled carburizing will take place resulting poor quality work.
Probe Burnoff Required?
Probe Burnoff Required
Two to Four inch Insertion
The purple and green pen represent the millivolt probe output on different scales. The red pen represents the probe thermocouple.
Summary: During burnoff the probe output should drop below 200 mV. As shown by green pen.