ANSI/AGMA C08 includes updated and extensively revised information from ANSI/AGMA B89 along with additional information needed to achieve . Download ANSI-AGMA B Gear Materials and Heat Treatment Manual. Index of AGMA Standards and Information Sheets by Number. 1 ANSI/AGMA B89 Gear Materials and Heat. Treatment Manual.
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AGMA gear rating standards should be consulted for appropriate stress numbers. Surface hardness is an important consideration for gear wear. 2004-b8 is becoming an accepted practice to specify shot peening on carburized and other heat treated gears. However, fatigue properties of this steel may not be equivalent to quench and tempered steel with the same tensile properties. Quenching, distortion, and shot peening are discussed. Underheating results in less than specified hardness and case 2004-b8.
This method produces a donutshaped work piece. Cast irons also have a high tendency for cracking.
It 22004-b89 necessary that the designer use a source of metallurgical knowledge of materials and processing. Machinery used for shot peening should be automatic and provide means for propelling shot by air pressure or centrifugal force against the atma. Abbreviations are used in the references to specific documents in this Standard. However, residual stresses from quench and tempering may be relieved at the nitriding temperature, causing distortion.
It is good practice to immediately temper after quenching if quench crack problems are a concern. Finer pitch gearing generally utilizes encircling coils with power provided by high frequency vacuum tube units.
The strength properties are closely related to material hardness, which is used in AGMA gear rating practice.
Martensite is the diffussionless transformation of austenite to a body centered tetragonal structure, characterized by an acicular needlelike appearance.
The normalizing and annealing processes are frequently used, either singularly or in combination, as a homogenizing heat treatment for alloy steels.
This standard is not included in any packages. Section size modification may be required along with added stock for grinding or 2004-b899 after heat treatment. Hardness in this area will be substantially lower.
These processes may also be used when the maximum contact and bending strength achieved by carburizing ayma not required. If masking is required, this should be stated in the shot peening requirements and defined on the drawing, aagma masked area tolerances given.
The spin flame process generally hardens below the roots, but hardens teeth through the 200-4b89 cross section, reducing core ductility of teeth and increasing distortion see Fig 20044-b89 When root is also to be hardened, depth of case at the root may be specified. Bores size may shrink up to 0. Wrought copper base materials is a general term used to describe a group of mechanically shaped gear materials in which copper is the major chemical component. Normalizing is used primarily to obtain a uniform microstructure.
This type of inspection may be necessary for accurate microhardness readings near the surface. Abney Fairfield Manufacturing R. To aid in obtaining the above characteristics, the heat treater should be given the following as a minimum: Rickt Auburn Gear H. Because the process increases bending fatigue strength, it may be used either to salvage or upgrade a gear design. Mechanical means for moving the work through the shot 22004-b89 by either translation or rotation, or both, should be provided.
Item Detail – ANSI/AGMA C08 (reaffirmed March )
Agmq publications are subject to revision, and the users of this standard are encouraged to apply the most recent editions of the publications listed. Outside Diameter of Casting, in mm To 12 Over 12 to 36 Over 36 to 60 Over 60 Number of Hardness Tests 1 2 4 8 When eight hardness tests are 2004-b98, they shall be made 90 degrees apart on both cope and drag side.
The induction coil method is generally limited to gears of approximately 5 DP and finer. The as quenched surface hardness is dependent primarily on the carbon content of the steel part and cooling rate. Gearing is removed from the heat source and immediately hardened by the quenchant.
ANSI-AGMA 2004-B89-1995 Gear Materials and Heat Treatment Manual
Silicon bronzes are commonly used in lightly loaded gearing for electrical applications because of their low cost and nonmagnetic properties. High surface hardness, high case strength, favorable compressive residual stress in the hardened case, and suitable core properties based on selection of the appropriate carburizing grade of steel, result in the highest AGMA gear tooth ratings for contact stress, pitting resistance and root strength bending.
Other AISI Type and proprietary chemical analyses are used for carbon and low alloy cast gears according to ASTM A or customer specifications, depending upon specified hardness mechanical propertiestype of heat treatment and controlling section size hardenability considerations.
Lower temperatures with longer holding times are sometimes used. Effective case depth is less frequently referred to as the depth to 0. Tolerancing must consider these changes. Spur gears are the easiest to produce out of powder metal because of the vertical action of the press and ease of ejection of the preform from the die cavity before sintering.
Normally, rough gear blanks forging, barstock, or casting have sufficient stock provided so distortion can be accommodated by machining. Burner head location must be precise from cycle to cycle. Gas carburizing consists of heating and holding low carbon or alloy steel less than 0.
Excessive tooth distortion and a ayma of core ductility can also occur.
This is characterized by an increase in carbon content with increasing depth; for example, when the peak carbon content is subsurface. For more information, consult the following: Contour induction hardening results 204-b89 case depth at the root to be approximately 60 percent of the depth at the pitchline due to mass quench and hardenabiltiy effect.
Hardness after tempering varies inversely with the tempering temperature used.