Multiple Pain Points Restrict Upgrading of Steel Plate Quenching and Tempering Machine, Intelligent Low-Carbon Transformation Becomes Industry Consensus

As core heat treatment equipment for manufacturing high-strength engineering machinery plates, pressure vessel steel, wear-resistant steel and bridge steel, steel plate quenching and tempering machine determine the mechanical property stability, flatness and yield rate of medium and heavy plates. China boasts the world’s largest medium-thick steel plate output, yet most domestic quenching and tempering production lines are trapped in prominent bottlenecks including unstable temperature control, poor plate shape correction, excessive energy consumption, low digitalization and vicious homogeneous competition, severely restricting the industry’s shift toward high-end, low-carbon and customized production.

Inaccurate temperature and uneven cooling stand as the primary technical defect of traditional quenching and tempering machines. Premium steel plates such as Q690 high-strength structural steel and low-temperature pressure vessel steel require furnace temperature deviation controlled within ±5℃ to guarantee uniform metallographic structure. However, most midstream and downstream complete equipment manufacturers adopt outdated single-zone heating furnaces with lagging pulse combustion control. Large-format steel plates suffer obvious temperature difference between core and edge during heating, leading to batch hardness fluctuation, local soft spots and inconsistent impact toughness after tempering. The roller quenching section faces greater challenges: conventional single-group fixed nozzles cannot adjust water pressure and jet angle in real time according to plate thickness, causing asymmetric cooling stress. Thin plates warp severely while thick plates fail to reach full quenching depth, pushing the rejection rate of high-end orders above 7%. Online closed-loop plate shape correction and real-time temperature monitoring systems are only equipped by less than 30% of leading enterprises; most manufacturers still rely on offline manual sampling inspection, unable to realize full-process quality traceability.

30000kw slab heat treatment line

High energy consumption and heavy environmental pressure squeeze enterprise profit margins sharply. Quenching furnaces, tempering furnaces and circulating cooling water systems account for over 30% of the total production cost of steel plate processing. Most old-style quenching and tempering machines lack waste heat recovery devices for flue gas and cooling water, with thermal efficiency lower than 65%, consuming massive natural gas and electric power throughout continuous operation. Meanwhile, quenching wastewater contains high-concentration rust and cooling additives, while furnace flue gas generates large amounts of nitrogen oxides and oxide scale dust. Upgraded national and international carbon emission and sewage discharge standards force factories to add extra environmental treatment equipment, further increasing transformation investment for small and medium-sized steel processing plants. Raw material prices of alloy steel plates fluctuate frequently, and combined with high energy expenditure, the gross profit margin of most processing enterprises falls below 15%.

steel billet induction heating machine

Low digitalization and homogenized competition widen the gap with foreign advanced equipment. Over half of domestic quenching and tempering production lines operate in semi-manual mode; heating speed, holding time and quenching water flow parameters are adjusted by workers’ experience without standardized digital process libraries. When switching between multi-specification, small-batch customized steel plates, parameter debugging takes several hours, greatly reducing line turnover efficiency. The industry has witnessed disorderly low-price competition in recent years: numerous small equipment integrators cut costs by simplifying furnace insulation, reducing nozzle groups and downgrading PLC control systems. Cheap quenching and tempering machines suffer frequent roller jams, temperature runaway and hydraulic system failure after short-term operation, damaging downstream manufacturers’ production schedules. In high-end markets including ultra-thick marine steel and aerospace structural steel, domestic complete sets of quenching and tempering equipment still lag behind European and American brands in precision control and long-term operational stability, with limited global market share and weak pricing power.