Quantcast 2-75.  MACHINING OF STEELS (GENERAL)

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
T. O. 1-1A-9 HEAT TREATMENT For maximum stress-rupture life in range 1560°1740°F, fully heat treat solution treat, and double age as follows: Solution treat  21020F  4  hours,  air  cool.    Double  age  19220F,  16  hours,  air  cool  and  1526°F,  8  hours,  air  cool.    Where  stress rupture strength above 1562OF is not the important property, but tensile strength, elongation and impact strength up to 1292OF is desired, the following heat treatment is recommended. Solution treat 21040F, 4 hours, air cool. Age 15620F, 16 hours, air cool. 2-75.  MACHINING OF STEELS (GENERAL) 2-76. There are five basic factors affecting machinability as related to steel: They comprise (1) the capacity and rigidity of the machine tool; (2) cutting fluids; (3) design composition and hardness of the cutting tool; (4) cutting condition with respect to feeds and speeds; and (5) the structure of the steel to be machined. 2-77.    The  cutting  tool  angles  (back  rake,  side  clearance,  front  clearance,  and  side  rake)  are  highly  important  in  the machining of metals.  The range of values based on general practice for the machining of steel and steel alloys, are as follows: (1) back rake angle, 8-16 degrees; (2) side rake angle, 12-22 degrees; (3) front clearance angle, 8-13 degrees; and (4) side clearance angle, 10-15 degrees. 2-78.  Regardless of the material of which the cutting tool is made, the cutting action is the same.  The main difference is the cutting speed.  The carbon-steel tool cuts at low speed.  The high-speed tool cuts at twice the speed of carbon-steel, the  cast  alloys  at  twice  the  speed  of  high-speed  steel,  and  the  sintered  carbides  at  twice  that  of  the  cast  alloys.    The cutting  speeds  listed  in  Table  2-4  are  approximate  speeds  using  high-speed  steel  tools,  and  are  to  be  used  only  as  a basis from which proper speeds for a particular part may be calculated.  These speeds are based on SAE  1112 steel, which is assigned a machin2bility rating of 100%.  In order to obtain an approximate starting speed for different steels, select the type of operation, the width, depth or diameter of cut and obtain the recommended cutting speed for SAE 1112 from Table 2-3 then refer to Table 2-4 for the percent rating of the metal to be machined, and multiply the SFM value from Table 2-5 by the rating in Table 2-4.  The result is the recommended surface feet per minute (SFM) for the cutting operation.    For  a  known  diameter  and  surface  feet  per  minute  (SFM)  to  be  used  for  an  operation,  the  corresponding revolution per minute (RPM) can be obtained from Table 2-5. 2-79.  The term cutting feed is used to express the axial distance the tool moves in each revolution.  A course feed is usually used for roughing operations, and a fine feed for finishing operations.  In general, the feed remains the same for different cutting tool steels, and only the speed is changed.  Approximate cutting feeds are listed in Table 2-3.  For tool corrections when improper machining on an operation is encountered, refer to Table 2-6 for recommended checks. 2-80. The use of a proper coolant (cutting fluid) often results in an increase of cutting speed for the same tool life, and also acts as a lubricant giving better cutting action and surface finish.  Recommended cutting fluids for steels are lard oil, mineral oils, sulphurized oils, and soluble or emulsifiable oils. 2-66

Aviation News
FAA and Industry Will Study Pilot Fitness
The FAA is working with the commercial aviation and medical...
faa.gov
Didier Evrard, Head of Programmes at Airbus, has been awarded the 2015 Icare prize
This prize distinguishes him for his key role in the...
airbus.com
FAA Streamlines COAs for UAS Test Sites
The Federal Aviation Administration has made it simpler for the...
faa.gov
NextGen's Next Big Thing
May 21- As we move into the summer thunderstorm season,...
faa.gov
FAA Expands "Lessons Learned" Safety Website
May 21- The Federal Aviation Administration (FAA) recently added six...
faa.gov
Volaris takes delivery of first two A321s
First airline in Mexico to operate Airbus’ largest single-aisle aircraft...
airbus.com
Sichuan Airlines receives its 100th Airbus aircraft
China’s largest all Airbus operator celebrates a land-mark delivery Share...
airbus.com
Airbus and Aerospace Valley foster eco-innovation
Partnership with Small & Medium Enterprises Share this Read more...
airbus.com
Airbus helps airlines further improve their environmental performance
Launches the Sustainable Aviation Engagement Programme Share this Read more...
airbus.com
ACSS T3CAS Surveillance System Sees Airbus ADS-B Certification
ACSS T3CAS. Photo: ACSS [Avionics Today 05-15-2015] L-3 and Thales...
aviationtoday.com
Rockwell Collins Scores NASA Contract to Develop Sonic Boom Cockpit Display
NASA’s initial depiction of sonic boom footprint integrated with real-time,...
aviationtoday.com
UH-1Y Recovery Efforts to Resume
@font-face { font-family: "Arial"; }@font-face { font-family: "MS 明朝"; }@font-face...
aviationtoday.com
VivaAerobus receives first of 52 A320s on order
New A320 marks next step towards fleet renewal for Mexico’s...
airbus.com
FAA Kicks Off "No Drone Zone" Effort for D.C. Area
May 13 As hundreds of thousands of tourists flock to...
faa.gov
TAM’s first A350 XWB takes shape
The first A350-900 for TAM Airlines is progressing well in...
airbus.com
Airbus BizLab business accelerator invites first project entries
Six month support to convert innovative ideas into valuable business...
airbus.com
Bird-deterring drones and game consoles inspire the future of flight
Student ideas in final race for €30,000 Airbus biennial Fly...
airbus.com
Boeing Looks to Turn Backlog into Growth
[Avionics Today 05-13-2015] At the 2015 Boeing Investor’s Conference on...
aviationtoday.com
Russian Helicopters Fly on Anniversary of End of WWII's Eastern Front
On Saturday, Russian Helicopters' Mi-26, Mi-28N Night Hunter, Mi-35M, Ka-52...
aviationtoday.com
Airbus Reports Fatal Accident Involving A400M Test Aircraft
Airbus A400M aircraft. Photo: Wikipedia [Avionics Today 05-12-2015] Airbus Defense...
aviationtoday.com

 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +