Rapid local annealing of high strength steel

• Main Authors: Huff, Garret Sankey, Chiriac, Constantin, Sohmshetty, Raj, Friedman, Peter A
• Format: Patent
• Language: English
• Published: 20.08.2019
• Subjects: ALLOYS; BLASTING; CHEMISTRY; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; ENGINEERING ELEMENTS AND UNITS; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; THERMAL INSULATION IN GENERAL; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

Systems and methods for locally softening high strength steel are disclosed. One method may include heat treating one or more local regions of a steel component having a hardness of at least 450 HV to soften the local region(s) to a hardness of at most 250 HV. The heat treating may include heating only the local region(s) to a target temperature above an AC1 temperature of the component and below an AC3 temperature of the component. In another method, the heat treating may include heating only the local region(s) to a first target temperature above an AC3 temperature of the component, cooling the local region(s) to below an AC1 temperature of the component, and isothermally holding the local region(s) at a second target temperature below the AC1 temperature. The locally softened region(s) may allow for improved joining and/or trimming of the component.