# US 2019/0320508 A1 · Microwave heating of boron steel blanks prior to the hot-stamping process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0320508 A1 - Document ID: US20190320508A1 - Status: Published application - Kind: A1 - Application number: 16/386,922 - Filed: 2019-04-17 - Published: 2019-10-17 - Earliest claimed: 2018-04-17 - Assignees: Materia Group Corporation - Applicants: Materia Group Ltd. - Inventors: David M. Vickers; Manoj Gupta; Terry Cable - Web page: https://patentgrep.com/patent/US20190320508A1 ## CPC - H05B 6/80: Apparatus for specific applications (stoves or ranges F24C7/02) - C21D 1/18: Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) - C21D 6/00: Heat treatment of ferrous alloys - C21D 9/46: for sheet metals - H05B 6/78: Arrangements for continuous movement of material - B21D 22/022: {by heating the blank or stamping associated with heat treatment (C21D takes precedence)} - B21D 37/16: Heating or cooling - H05B 2206/04: Heating using microwaves - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F) ## Abstract A method of heating a steel blank using a microwave heating furnace system for the hot stamping process includes providing a steel blank having a thickness ranging from 1 mm to 1.8 mm, pre-heating the streel blank to an initial temperature in a pre-heat chamber of the microwave heating furnace system, and directly heating the steel blank using microwave energy in a main heating zone of the microwave heating furnace system from the initial temperature to a temperature greater than 850° C. in less than 240 seconds. ## Claims ### Claim 1 A method of heating a metal blank using a microwave heating furnace system for a hot stamping process, the method comprising the steps of: providing a metal blank having a thickness ranging from 1 mm to 1.8 mm; pre-heating the metal blank to an initial temperature in a pre-heat chamber of the microwave heating furnace system; and directly heating the metal blank using microwave energy in a main heating chamber of the microwave heating furnace system from the initial temperature to a temperature greater than 850° C. in less than 240 seconds. ### Claim 2 (depends on 1) The method according to claim 1, wherein the main heating zone includes two or more heating sub-zones, each sub-zone configured to increase a temperature range. ### Claim 3 (depends on 1) The method according to claim 1, wherein the steel blank is a boron steel blank. ### Claim 4 (depends on 1) The method according to claim 1, wherein the initial temperature is between 350° C. and 400° C. ### Claim 5 (depends on 1) The method according to claim 1, wherein the pre-heat chamber has a height greater than its width. ### Claim 6 (depends on 1) The method according to claim 1, wherein the pre-heating is done by microwave energy. ### Claim 7 (depends on 1) The method according to claim 1, wherein the pre-heating is done by thermal heating. ### Claim 8 (depends on 3) The method according to claim 3, wherein the boron steel blank is being heated using 100% microwave heating. ### Claim 9 (depends on 3) The method according to claim 3, wherein the heating energy for heating the boron steel blank is partially microwave energy. ### Claim 10 (depends on 1) The method according to claim 1, wherein the microwave heating furnace system further comprises a conveyor system for transporting the steel blank and silicon carbide nanocoated pins used to hold the steel blank in place on the conveyor system. ### Claim 11 (depends on 1) The method according to claim 1, wherein the microwave heating furnace system further comprises a conveyor system for transporting the metal blank and silicon carbide nanocoated hooks or clips used to hold the metal blank in place on the conveyor system. ### Claim 12 (depends on 1) The microwave heating furnace system according to claim 1, wherein the pre-heat and the main heating zone each comprise a steel mesh curtain or door to shield the microwave both into and out of the pre-heat chamber. ### Claim 13 A microwave heating furnace system for heating metal blanks for hot stamping, comprising: an incoming feed for feeding a metal blank into the furnace system; a pre-heat chamber for heating the metal blank to an initial temperature; a main heating zone adjacent to the pre-heat chamber having at least one heating sub-zone, the main heating zone configured to heat the metal blank from the pre-heat chamber to a second temperature in a processing time between 180 and 240 seconds; an outgoing section for transferring the metal blank to a subsequent hot stamping process; and a continuous conveyor system from the incoming feed through the pre-heat chamber and the main heating zone to the outgoing section for transferring the metal blank to the hot-stamping process. ### Claim 14 (depends on 13) The microwave heating furnace system according to claim 13, wherein the metal blank is a boron steel blank. ### Claim 15 (depends on 14) The microwave heating furnace system according to claim 14, wherein the boron steel blank has a thickness ranging from 1 mm to 1.8 mm. ### Claim 16 (depends on 13) The microwave heating furnace system according to claim 13, wherein the initial temperature is between 350° C. and 400° C. ### Claim 17 (depends on 13) The microwave heating furnace system according to claim 13, wherein the second temperature is greater than 850° C. ### Claim 18 (depends on 13) The microwave heating furnace system according to claim 13, wherein the main heating zone includes two or more heating sub-zones, the heating sub-zones configured to heat the metal blank from the pre-heating chamber to graded temperatures.