Nov_Dec_AMP_Digital

FEATURE A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 1 7 5 9 14 billet heating, and the intensivewater quench actually blasts off any forging scale, eliminating the need for blast cleaning. Because DFIQ consistently quenches the part, it aids in the production of a more near-net-shape part after hardening. INTENSIQUENCH REDUCES COST OF MANUFACTURING Three types of IQ processes used for final heat treat- ment of steel parts include: • Batch IQ —parts are batch furnace heated and inten- sively quenched in an IQ water tank • Continuous IQ —parts are heated in a continuous furnace and intensively quenched in a continuous IQ water tank • Single-part quenching —an individual part is quenched in high-velocity water-flow IQ system after furnace or induction heating IQT has conducted hundreds of IQ demonstrations for a variety of steel parts using batch and single-part process- ing IQ equipment installed at Akron Steel Treating Co. and at Euclid Heat Treating Co. in Cleveland. Proven IQ process benefits include: • Increased surface and core hardness with a deeper hardened layer (up to 50%) resulting in stronger parts or lighter parts with a higher power density. • Use of less expensive, lower alloy steels producing the same mechanical properties as higher alloy materials that are conventionally quenched in oil and water-based polymers. This is in contrast to material selection by part designers using traditional heat treat- ment where added strength usually requires selection of steels containing additional alloying elements for higher hardenability. • High residual surface compressive stresses in parts made of through-hardening steels (in contrast to ten- sile stresses after convectional quenching) resulting in stronger parts with longer fatigue life. • Up to two times greater residual surface compressive stresses in parts made of carburized steels compared with conventional quenching in oil, without mechani- cal shot peening. • Low, repeatable part distortion (as low as 50 µm) for predictable part size change after hardening. Distor- tion is so predictable, the green part can be purposely machined out of tolerance and will consistently distort to fit after IQ hardening. • Reduced heat treatment cost due to a reduction in furnace carburization cycle times by 30-40%, which re- sults in higher furnace production rates, lower energy costs, cleaner parts, and no hazards or environmental concerns associated with oil quenching. For a given alloy’s inherent hardenability, the “hardenability” built into the IQ process requires less carbon content in the case gradient to achieve an effective case depth hardness of 50 HRC compared with oil and water-base polymer quenching. • Enables the elimination of carburizing with the use of optimum hardenability steels [1] , and also enables sin- gle-part flow in the manufacture and heat treatment of case-hardened parts in the manufacturing cell. This in turn allows for lower work-in-process inventories, as well as faster, more flexible throughput for case-hard- ened parts. IQ Technologies recently shipped a $1.1 million, fully automated turnkey IntensiQuench system for hardening gear products consisting of a rotary hearth, controlled-at- mosphere furnace for austenitizing parts prior to quenching, a single-part processing IQ unit, and a pick and place device to transfer parts from the furnace to the IQ unit and from the IQ unit to the unloading area (Fig. 4). The systemenables the manufacturer to use plain carbon steel instead of an alloy steel; to reduce the carburizing cycle time by up to 30%; to eliminate the environmental costs of oil quenching; and to minimize straightening opera- tions for its gear products. In addition, shot peening can be eliminated for some parts. CONCLUSION Lean manufacture of parts re- quires that each step in the manufac- turing value stream be concurrently engineered to eliminate waste wher- ever andwhenever possible. Each pro- cessing step, including heat treating, should be fully integrated into the part Fig. 4 — Fully automated, single-part processing IntensiQuench system for hardening gears. 15