Induction hardening, although a safe repeatable process, can require a lot of tuning whenever an input parameter or inductor is changed. This paper discusses the nature of the problem and how it can be alleviated using 3D technology. It explains that long setup times and tedious adjustments after tooling changes are due to inaccuracies in the inductors and their positioning relative to the workpiece. It then describes how these inaccuracies are removed using 3D construction, production, measurement, and positioning technology, including FEA and CFD software, laser powder bed fusion, and optical scanning. To verify the approach, two inductors were additively manufactured and tested in a hardening system. The first inductor was used to harden a bearing seat on a shaft. The inductors were then swapped and another part was hardened without any adjustment to the process. The hardening depth and surface hardness of the two parts are identical within the scope of measurement accuracy.

This paper investigates the factors that influence quenching rates and temperature distributions in steel during dilatometry testing. In a prior study, the authors assessed the performance of the cooling system in a widely used dilatometer. The goal of the current work is to develop a cooling strategy that provides more uniform and possibly faster cooling in the same system. Several alternate quench concepts are analyzed, the most promising of which uses water-cooled tubes to deliver high velocity gas through a series of jets axially aligned with the test sample. The proposed cooling apparatus and its effect on the induction heating process are assessed using CFD, electromagnetic, and thermal analyses.

Quench and tempering heat treating operations for tubular products are relying more on induction equipment. The reasons for this can be traced to the lower energy costs for operating induction equipment compared to gas furnaces and the greater flexibility that the induction lines offer compared to their furnace counterparts in regards to recipe control and product mix. However, there are limitations and special considerations for induction heat treating equipment and the induction coils used for these operations. This paper reports on the design and operation of a new induction heat treating line for API 5CT grade L80 and P110 casing and tubing with upset ends. Upset ends pose special technical challenges for induction heating; the generation of a uniform temperature distribution relies heavily on proper coil design as well as line layout and heating time. Simulations of induction heating have provided predictions of heating profiles, and on-the-line testing allowed recipe refinement and validation of simulation models. Results from this case study help to increase confidence in this heat treating process as well as create an improved induction heating line layout for future applications.