Melting and Heat Treating
Our cast steels are manufactured in two basic electric arc furnaces with capacities of 5 and 70 tons. Precise alloy additions are determined through computer aided melting coupled with statistical process control, and are monitored by spectrographic analysis. The optimum balance between strength and toughness is achieved either through annealing, normalizing and tempering, or through quenching and tempering.

Our heat treat furnaces are equipped with programmable controllers to allow for complete control of critical times and temperatures. The largest heat treat furnace measures 30' x 40' x 12' and allows us to do all heat treating in house. This permits close quality control over all aspects of manufacturing. For the infrequent times that machining sequenes or other manufacturing considerations require that heat treating be performed at the customer's plant, our castings can be furnished in the annealed condition. The recommendations shown in Table 8 are provided as a guide.

TABLE 8 - Recommendations for Heat Treating Castings ¹
GRADE	Annealing			Normalizing & Tempering ²				Quench Hardening			Tempering after Quenching ²			Stress Relieving
	Temp. +/-25^oF	Time ³ at Temp.	Method of Cooling	Temp. +/-25^oF	Time ³ at Temp.	Method of Cooling	Minimum Tempering Temp (^oF)	Temp. +/-25^oF	Time ³ at Temp.	Method of Cooling	Min. Temp. ⁵ (^oF)	Time ³ at Temp.	Method of Cooling	Temp (^oF)	Time ³ at Temp.	Method of Cooling
Moly-Telastic	1600	45-60	Furnace Cool to below 850^oF	1600	45-60	Air	1000	1575	45-60	Water ⁶ or Oil ⁴	900	45-60	Air or Furnace	See Note ⁷	45	Air or Furnace
No. 1 Gearalloy	1600	45-60	Furnace Cool to below 850^oF	1575	45-60	Air	1000	1575	45-60	Water ⁸ or Oil ⁴	900	45-60	Air or Furnace	See Note ⁷	45	Air or Furnace
No. 2 Gearalloy	1700	45-60	Furnace Cool to below 850^oF	1700	45-60	Air	. . .	1700	45-60	Water	1000	45-60	Air or Furnace	See Note ⁷	45	Air or Furnace
No. 3 Gearalloy	1600	45-60	Furnace Cool to below 850^oF	1575	45-60	Air	1000	1575	45-60	Oil ⁹	900	45-60	Air or Furnace	See Note ⁷	45	Air or Furnace
No. 4 Gearalloy	1600	45-60	Furnace Cool to below 850^oF	1525	45-60	Air	1000	1500	45-60	Oil ⁹	900	45-60	Air or Furnace	See Note ⁷	45	Air or Furnace
No. 6 Gearalloy	1600	45-60	Furnace Cool to below 850^oF	1525	45-60	Air	1000	. . .	. . .	See Note ¹⁰	. . .	. . .	. . .	See Note ⁷	45	Air or Furnace
¹ Tempering temperatures vary depending upon specified hardness, chemical analysis, and controlling section size. Falk will provide information and recommendations for any particular customer heat treatment application upon request. ² Time at temperature and method of cooling for tempering after normalizing, shall be the same as for tempering after quench hardening. ³Minutes/Inch of maximum section at temperature, depends upon accuracy (condition) and temperature variance of the furnace. Forty-five Minutes/Inch hold time may be used with more accurate and uniform furnaces. ⁴Oil or equivalent synthetic quenching is used when design considerations increase susceptibility to quench cracking. ⁵Use highest possible tempering temperature to obtain specified hardness and/or mechanical properties. ⁶Moly-Telasic is primarily hardened by water quenching (130-140^oF). ⁷1100^oF or 50-100^oF below tempering temperature, whichever is less. ⁸No. 1 Gearalloy is commonly hot water quenched (130-180^oF). ⁹Oil or equivalent synthetic quenchant. ¹⁰No. 6 Gearalloy is not recommended for quench hardening.

Nondestructive Testing

As a user of castings which require a great deal of machining, we realize the need for quality control throughout all phases of manufacture, to assure the integrity of the part after rough and/or finish machining.

Prior to final heat treatment, all castings are nondestructively tested using magnetic particle inspection. Whenever possible, process welding is performed prior to final heat treatment. All welds are magnetic particle inspected to ensure their integrity. After heat treatment, castings are again given a complete magnetic particle inspection.

If specified, additional nondestructive testing, such as ultrasonic or radiographic inspection, is performed to ensure the internal integrity of the casting.

Processing Operations

The sequence of foundry processing operations is as follows:

1. Preproduction Analysis
Drawings, material specifications and all nondestructive testing requirements are analyzed. Layouts are made to determine riser sizing and wedging. Using computer programs, foundry engineers calculate proper riser sizes, location and the necessary gating. Pattern construction details are resolved and the pattern is constructed. After construction, the pattern is dimensionally checked before releasing for production.

2. Moulding/Coremaking Processing
During both operations, into ensureprocess inspections are critical to ensure the following: Dimensional accuracy. Proper pouring height and mold cleanliness. Proper size and location of all risers and gating systems.

3. Melting Analysis
Computer-aided melting is used, coupled with statistical process control, to melt to a harden ability range that will ensure uniform response to heat treating. The melt shop personnel have a "go"/ no go criteria established by a computer program. Actual chemical analysis is determined through spectrographic analysis and is recorded.

4. Pouring the Casting
Precise pouring instructions are established and monitored. Results are recorded.

5. Cooling
Thermocouples monitor temperatures to determine the proper time for shakeout.

6. Shakeout
Removes a high percentage of the adhering sand from the casting.

7. Inspection
Prior to gas cutting. the casting is visually inspected to ensure that it was poured to the proper pouring height. The proper cut-off height for riser removal is established. Riser removal temperatures, of at least 350*F are monitored.

8. Gas Cutting
A semi-automatic gas cutting machine is used for riser removal.

9. Annealing
Full annealing is required to alleviate stresses that developed during the solidification of the casting and also to remove any stresses that may have developed during gas cutting.

10. Shot Blasting
Removes heat treat scale.

11. Rough Clean
Includes arc air of pads and fins, stress relieving and blasting.

12. Inspection
Rough casting layout. Dimensions are recorded to ensure proper as-cast tolerances. Critical areas, such as rim l.D., pocket radii and bolting flanges are ground for dry magnetic particle inspection. Entire casting is also given a 100% wet magnetic particle inspection if specified. All results are recorded.

13. Preheat Casting
Furnace preheat for defect removal.

14. Defect Removal
Defects are removed by arc air.

15. Inspection
Magnetic particle inspection is performed to ensure complete defect removal. Defect size and location are recorded.

16. Upgrade
Whenever possible, all process welding is performed prior to final heat treatment using heat treatable electrodes. Welding is done by qualified welders, and when required, according to qualified procedures. Furnace preheating and furnace stress relieving are utilized.

17. Final Heat Treatment in Car-bottom Furnaces
Furnaces are run with programmable controllers. Furnace charts are available upon request.

18. Inspection
Upgraded areas and all critical areas are again magnetic particle inspected. Brinell readings are taken to ensure casting is within specified hardness range. Layout and rough dimensions are recorded after heat treatment to ensure sufficient stock for machining. Defect sketches are recorded both before and after final heat treatment. Any defects that become apparent after anal heat treatment are subjected to the procedures as noted in points # 12 through #16. If required, the casting will receive a complete reheat treatment. If required, test bars are pulled to verify mechanical properties.

19. Finishing
Rough and/or Finish Machining and Additional NDT Requirements Ultrasonic and/or radiographic inspection per the appropriate specification. Magnetic particle inspection. Brinell readings in designated areas. All results are recorded.