The long product sector, a cornerstone of the global steel industry, is undergoing a transformative technological evolution focused on Efficiency, Quality, Green Development, and Smart Operation. Driven by the pursuit of integrated economic, ecological, and social benefits, these innovations are breaking industry bottlenecks, optimizing full-process production, and empowering steel enterprises to achieve high-quality development and sustainable competitiveness.
Efficiency Upgrading: Dual Breakthroughs in Technology & Equipment
Efficiency is the core goal of technological innovation in long product production lines. Comprehensive upgrades in rolling concepts, flexible rolling technology, mill equipment, flying shear technology, and material tracking systems have achieved a qualitative leap in production efficiency, while reducing operational costs and improving process stability.
1. Optimized Single Pass Rolling Concept
The new high-speed bar rolling line adds only 2 rolling stands, significantly reducing roll change frequency and slitting failure rates. Simplified pass design cuts the total number of basic passes in the whole line, lowering workers’ operational intensity and effectively improving equipment operation rate.
2. Advanced Flexible Rolling Technology for Bars & Wires
Modular rolling mills represent a core breakthrough, modularizing the “oval-round” rolling unit to enable precise temperature control via water cooling between mills and flexible adjustment of single-pass elongation. The technology simplifies equipment structure, reduces roll ring consumption and spare parts inventory, and cuts power consumption per ton of steel.
- High-speed bar line: Design speed 50m/s (stable operation at 45m/s)
- High-speed wire line: Design speed 140m/s (stable operation at 112m/s)
3. Iterative Upgrades of Rolling Mill Equipment
- Reversible traversing breakdown mill: Achieves ±0.3mm traversing accuracy and ±0.2mm roll gap adjustment accuracy, meeting high dimensional precision and fast process gap requirements.
- Next-gen intelligent short-stress path mill: Equipped with intelligent loaded screw down, automatic roll gap adjustment, and rapid stand change, laying the hardware foundation for one-click intelligent steel rolling.
- Horizontal-vertical composite mill: Replaces traditional horizontal-vertical conversion mills, realizing independent horizontal/vertical installation in a single stand to meet both single-line and slitting rolling needs, solving pain points such as stand deformation, severe vibration, and high failure rates.
4. Advanced Flying Shear Technology
Ultra-high-speed flying shears (80~120m/s), 450-ton high-shear-force shears, multi-line slitting shears, and 125-ton traversing combined shears are widely applied, balancing shear speed, force, and flexibility to match high-speed rolling rhythms.
5. Full-Coverage Material Tracking Technology
From billet inspection and coding at the furnace charging area, to logical + visual tracking during rolling, to on-line laser marking and automatic counting/scanning in the finished product collection area, and intelligent three-dimensional warehousing in the finished product warehouse, the whole-life cycle material traceability is realized, providing accurate data support for quality control and production management.
Quality Improvement: Full-Process Optimization for High-End Products
Focusing on product quality, the comprehensive promotion of controlled rolling & cooling, high-precision rolling, on-line finishing and heat treatment technologies has achieved an all-round upgrade in the mechanical properties, dimensional accuracy and surface quality of long products, meeting the high-end market demand for special steel and high-performance rebar.
1. Popularized Controlled Rolling & Cooling for Rebar
In line with the new national standard for hot-rolled rebar, the low-temperature finish rolling + post-rolling graded cooling process refines grain structure, improves internal organization, and enables low-cost production of high-quality rebar with reduced vanadium and manganese. Multi-channel water cooling devices are configured for the production line, adopting differentiated multi-line slitting/single-line rolling processes for different specifications to ensure product strength and surface quality.
2. Widely Applied High-Precision Rolling Technology
Mature two-roll, three-roll and four-roll sizing/reducing technologies have been implemented, achieving dimensional accuracy of 1/4~1/6DIN:
- Three-roll sizing/reducing: Adopts 120° torsion-free rolling, widely used in special steel bar and coil production lines.
- Four-roll sizing/reducing: Realizes segmented precise control of reducing and sizing, applied in high-precision small bar production lines.
3. Integrated On-line Finishing & Heat Treatment
- Bar production lines: Equipped with on-line chamfering devices to remove burrs at 100%, combined with high-temperature slow cooling and on-line straightening technologies to improve the end and surface quality of finished products.
- Wire production lines: Adopt on-line water bath EDC and salt bath DLP technologies to greatly improve cooling rate and uniformity, enhance material mechanical properties and sorbite ratio; on-line tunnel furnaces realize isothermal transformation and precise slow cooling of wire coils, providing process support for special steel production.
Green Development: Energy Saving & Emission Reduction for Carbon Neutrality
Green and low-carbon development has become a key direction for long product production lines. Efforts in energy consumption reduction, waste heat recovery and pollutant control have realized energy saving, consumption reduction and emission reduction in the production process, helping steel enterprises achieve carbon neutrality goals and lower comprehensive production costs.
1. Core Energy-Saving Technologies
Hot charging and direct rolling technologies replace traditional reheating furnace processes, reducing gas and water consumption, cutting billet oxidation loss, and achieving zero emissions of particulates, NOx and SOx. The comprehensive cost per ton of steel can be reduced by 30~60 CNY, with optimized dynamic matching of the casting-rolling interface to minimize the impact of direct rolling on production capacity.
2. Efficient Utilization of Waste Heat & Clean Energy
- Waste heat recovery: The waste heat recovery system for bar cooling beds and wire air cooling lines absorbs rolling waste heat through heat exchangers to generate 0.9MPa saturated steam for external supply, realizing secondary energy utilization.
- Photovoltaic power generation: BAPV/BIPV photovoltaic systems are promoted on the roof of steel rolling workshops, converting building roofs into clean energy production ends and reducing enterprises’ reliance on external power purchase.
3. Precise Full-Process Pollutant Control
- Heating furnaces: Adopt air staging flameless combustion and ultra-low NOx control technologies, with stable NOx emissions below 100mg/m³; equipped with dry SDS desulfurization + SCR denitrification devices to meet the latest national emission standards for atmospheric pollutants in the iron and steel industry.
- Rolling mill area: Adopt plastic sintered plate/wet vortex dust removal; bag-type dust removal is configured for abrasive sawing and shot blasting areas, with waste gas pollutant emissions below 10mg/Nm³.
Smart Empowerment: Full-Process Digital Control for Smart Factories
Centered on digitalization and intelligence, the integration of machine vision, industrial robots, cloud-edge collaboration and digital twin technologies has realized full-process intelligence from equipment operation and production process to enterprise management, building an integrated ecosystem of Smart Equipment – Smart Workshop – Smart Factory.
1. Full-Scenario Machine Vision Application
The combination of laser radar and industrial cameras enables full-process visual monitoring including rolling pile detection, bar length alignment detection, automatic billet number recognition, finished product collection tracking and laying loop shape monitoring, capturing production anomalies in real time and improving automation and production stability.
2. Industrial Robots in Multiple Positions
Sampling robots, marking robots, inspection robots and production auxiliary robots are fully deployed to realize automatic sampling/delivery, on-line laser marking, automatic welding labeling/scanning, hazardous environment inspection and waste hopper cleaning, replacing manual work for high-intensity, high-risk and repetitive operations, reducing labor costs and improving production safety and efficiency.
3. Full-Link Integration of Digital Intelligence Technology
- Cloud-edge collaboration architecture: The workshop edge data center realizes on-line production optimization, equipment operation and maintenance monitoring and real-time quality inspection; the enterprise cloud data center completes production plan optimization, energy scheduling, cost analysis and enterprise decision-making.
- Digital twin: Based on BIM and simulation technologies, an engineering data center and digital twin scenario are built to realize digital delivery of engineering construction and automatic accumulation of production operation data, forming a full-life cycle digital intelligent factory based on smart operation and maintenance and smart management.
Industry Trend: Technological Innovation Drives High-Quality Development
The development of the long product industry proves that there are no backward industries, only backward enterprises. Driven by the new industrial revolution and carbon neutrality goals, technological innovation focusing on efficiency, quality, green development and intelligence will remain an eternal theme for the development of long product production lines.
In the future, the core competitiveness of long product enterprises will lie in the iterative capability of process technology, the intelligence level of equipment, the green and low-carbon production mode and the full-process digital control. Only by continuously deepening technological innovation and promoting the upgrading and transformation of the entire production process can enterprises seize the initiative in industry competition, achieve sustainable development, and inject core impetus into the high-quality development of the global steel industry.
