February 2024 Volume 6

EQUIPMENT & TECHNOLOGY

Hub

Yoke

Stopper

Pintle adapter

Clamp

Spur gear shaft

Fig. 4: Manufacturing process flow chart It was also shown that, in many cases, the DFIQ eliminates all post forging heat treatment, resulting in significant cost savings and production lead time reductions. Additionally significant benefits were demonstrated: • Reduced or elimination of geometrical distortion minimizing or negating the need for straightening operations • Reduced or elimination of part cracking • Improved mechanical properties due to better material microstructure • Reduced energy consumption by eliminating reheat steps prior to final heat treatment • Reduced material costs via the potential substitution of low alloy steel for high alloy steel with equivalent or improved mechanical properties Steel forgings ideally suited for DFIQ include: 1. Components seeking cost reduction either through reduction of energy costs or material costs. 2. Components suited for automation with the integration of billet sizing and cutting, induction heating, robotic manipulators throughout the process, and intensive quenching. Integration of in line sensors can ensure component quality. 3. Components ripe for reduction of greenhouse gas emissions. 4. Components dependent on potentially hazardous oil quenching systems. 5. Components requiring carburizing which are burdened with long carburizing cycles which can be replaced with the IQ induced surface treatment resulting in the requisite surface hardness sought by the customer. Based on the published case studies generated in earlier programs and new, customer proprietary programs with Ajax TOCCO Magnethermic, DFIQ is ready for commercialization. Coupling Intensive Quenching with Induction Heating provides even more value to the customer of steel components.

Key

Lug

Fig. 3: Examples of forgings subjected to DFIQ process

5. DFIQ Benefits for Forging Companies The DFIQ process can be used successfully to produce microstructures and mechanical properties that meet product requirements. The strengths and hardnesses of the DFIQ’ed forgings were acceptable in all cases. The strength properties tended to be higher for DFIQ forgings, most likely due to a higher cooling rate. The applicability of DFIQ is subject to the hardenability of the steel being used, part geometry, and the manufacturing steps that follow the forging operations. The material microstructures of the production DFIQ forgings appears to be similar to that of the forgings after a conventional post-forging heat treatment, and in some cases, the DFIQ microstructure was found to be slightly coarser, but still acceptable, than the conventionally processed forgings. The use of the DFIQ results in tremendous energy saving by (1) eliminating one or more reheat steps prior to final heat treatment, (2) eliminating environmentally unfriendly and hazardous quench oils and associated costs, and, in some cases, by eliminating a post forging heat treatment process completely. The latter, in turn, results in a significant reduction of production lead time, up to 8 days for some parts. Fig. 4 presents current and proposed manufacturing process flow charts for the pintle adaptor (see Fig. 3) subjected to DFIQ. Additionally, the material characterization analysis discussed previously proves the DFIQ process benefit enables the substitution of lower alloy steels for high alloy steels, resulting in significant material cost savings.

FIA MAGAZINE | FEBRUARY 2024 24