Technical Analysis: Core Penetration Heating Parameters of Steel Plate Hot Rolled Induction Heating Equipment

As continuous hot rolling lines pursue low energy consumption and stable product metallurgical performance, IGBT-based steel plate induction through-heating equipment has gradually replaced traditional gas furnaces and resistance furnaces. The precision matching of penetration heating parameters directly determines plate temperature uniformity, rolling yield and production cost. This article systematically sorts out the core controllable parameters of the equipment and their application standards for carbon steel, alloy Steel plate hot rolled induction heating equipment

Frequency is the primary parameter deciding eddy current penetration depth, which follows the inverse square root relationship with penetration depth δ. For steel plates with thickness 15–80mm for hot rolling, medium frequency 1kHz–3kHz is the standard configuration; plates thinner than 15mm adopt 4kHz–8kHz superaudio frequency to balance surface heating speed and core temperature consistency. When steel temperature exceeds Curie point (770℃), steel magnetic permeability drops sharply, and low frequency ensures deep penetration to avoid surface overburning while the plate core fails to reach rolling temperature. Optimized frequency matching controls thickness-direction temperature difference within ±20℃, eliminating hidden dangers of uneven rolling deformation.

Steel plate heat treatment equipment

Target heating temperature and temperature fluctuation tolerance are critical metallurgical indicators. Conventional hot rolling forming temperature ranges from 1050℃ to 1200℃; low-carbon steel is set at 1100–1150℃, alloy structural steel at 1180–1220℃. The equipment’s closed-loop infrared temperature control system limits overall plate temperature fluctuation within ±15℃, axial and thickness direction differential temperature below 30℃, far superior to ±50℃ index of traditional furnaces. Stable temperature field greatly reduces plate edge cracking, thickness deviation and post-rolling residual stress.

Auxiliary supporting parameters guarantee long-term stable penetration heating. Circulating cooling water pressure must stay above 0.5MPa, inlet water temperature controlled below 55℃ to protect induction coils and power modules; coil length is matched with plate travelling speed to form effective uniform temperature zone over 300mm, eliminating cold zones at plate head and tail. Under full-load continuous production, the equipment’s energy consumption is controlled at 330–360 kWh per ton of steel, saving over 40% energy compared with gas heating furnaces, with metal oxidation loss reduced by 70%.