With Germany’s “Industry 4.0”, the United States “National Strategic Plan for Advanced Manufacturing”, Japan’s “Science and Technology Industry Alliance” and China’s “Made in China 2025” these national strategies have been successively proposed and deepened. Towards the direction of automation, digitization, networking, intelligence, and greening. As a typical representative of the advanced manufacturing industry, the industrial robot industry is showing explosive growth.
Industrial robots are complex intelligent machines with automatic positioning control, reprogrammable, multi-functional, and multi-degree-of-freedom, which integrate advanced technologies in various disciplines such as machinery, electronics, control, computers, sensors, artificial intelligence, and control technology. Since the early 1960s, after decades of development, industrial robots have been widely used, and their advantages are mainly reflected in high work efficiency, good stability and reliability, good repeatability, and the ability to work in high-risk environments. For the iron and steel industry, where labor costs are rising year by year, the use of robots to replace manual labor is the general trend and future direction of the development of the iron and steel industry.
Analysis and development trend of the iron and steel industry
1) Issues in the steel industry
In recent years, the level of digitalization and networking in my country’s iron and steel industry has been significantly improved, but the resource consumption and energy consumption in the iron and steel production process are still too large, the process technology and equipment lack independent innovation, and the application and promotion of environmental protection and energy-saving technologies are not enough, which has a negative impact on resources, energy, and the environment. greater pressure.
The structure of iron and steel products is unbalanced, low-end production capacity is overcapacity, high-end supply is insufficient, and some high-performance steel products urgently needed for economic construction and national defense security cannot be fully produced for the time being. The steel industry urgently needs to improve its ability to produce high-end products.
The iron and steel production process and product quality control capabilities are insufficient, and production efficiency needs to be improved urgently. The level of automation and intelligence is not enough. There is a lot of manual intervention in the production process, resulting in unstable product quality and relatively low production efficiency.
2) Industry development trend
According to the current problems in the steel industry, the development of the steel industry in the next few years will include the following aspects: First, the industrial structure will continue to be optimized and product quality will continue to improve; second, the industrialization and informatization of the steel industry will be deeply integrated, especially IoT sensor technology, artificial intelligence technology, and deep learning algorithms will be more widely used; third, production control will be more intelligent, especially for jobs with the harsh working environment, high labor intensity, and high-risk factor, which will basically be unmanned.
It is not difficult to see that, as a process-based manufacturing enterprise, the iron and steel industry, with the gradual popularization of intelligent applications, has become a recognized development trend with the help of intelligent means to achieve overall optimization of industry-wide resource allocation and improve efficiency and quality.
The application of robots in the steel industry
1) Composition of robots
The robot is mainly composed of a mounting frame, a robot positioning system, a servo drive system, a machine gripper, a control system, and safety protection devices.
(1) Robot mounting bracket
The mounting frame is used to support the robot to ensure its stability of the robot during rapid positioning movement. The mount needs to be very rigid. Therefore, we use the welded steel frame structure as the supporting frame.
(2) Robot positioning system
The robot positioning system is the core of the whole device, including visual positioning, wireless network, radio frequency identification, and other related knowledge. The positioning problem can also be described as the process of determining the correspondence between the local coordinate system of the robot and the global coordinate system, that is, determining the pose of the robot.
(3) Servo drive system
Each motion axis of the robot is equipped with a servo motor and a reducer. The robot electric servo drive system is an actuator that directly or indirectly drives the robot body to obtain various movements of the robot by using the torque and force generated by various motors.
(4) Robot gripper
A robot with a gripping action is usually equipped with a manipulator. The pressure of the manipulator is adjustable, and it is equipped with a pressure buffer valve to ensure stable clamping action. The gripper is equipped with a sensing mechanism, which can automatically sense the object and notify the control center to pick and place the object.
(5) Control system
The control system is composed of a large PLC and touch screen. The system has a powerful Profibus communication function. It can transmit data to Ethernet in real-time and can send control instructions to the servo system in the form of a bus so that the movement is smooth. The system can usually present a variety of workpiece programs, and the corresponding programs can be called on the touch screen when changing varieties.
(6) Safety protection device
The robot needs to have fault prompt and alarm functions. When a fault occurs, it needs to accurately reflect the specific location of the fault, so as to facilitate rapid troubleshooting.
2) Necessity of robot application
In the iron and steel industry, the replacement of manual operations by industrial robots mainly has the following advantages:
(1) Replace labor-intensive jobs.
For highly repetitive and labor-intensive operations, robot operations can greatly reduce the intensity of labor and avoid injuries caused by repetitive labor. Such as driving, slag removal, handling, and other positions.
(2) Substitute high-risk positions.
For some operations in the iron and steel industry that have toxic and harmful gases and high-temperature harsh environments, using robots to replace manual operations can protect workers from harsh environments and improve operating standards and labor efficiency. Such as temperature measurement and sampling, welding, spraying, and other posts.
(3) Replace jobs with harsh working conditions.
For some dusty and harsh environment operations in the iron and steel industry, robots are used to replace manual operations, such as mixing, stacking and reclaiming, and workshop cleaning in raw, fuel, and auxiliary material factories, which can protect workers from harsh environments and improve Operating standards and labor efficiency.
(4) For standard operations such as quality inspection, temperature measurement, and sample inspection, robotic operations can avoid misjudgments, wrong judgments, and inaccurate measurements caused by human errors, which is conducive to the realization of standardized operations.
(5) Realize the digitalization and informatization of traditional crafts through industrial robots, and use the communication capabilities of robots to realize the “non-landing” of data flow, which greatly improves the timeliness and accuracy of information transmission on the production line.
Application examples of robots in the steel industry
At present, the application of robots in the iron and steel industry mainly focuses on the following aspects:
1 Raw material factory
Belt inspection robot
Realize the automatic inspection of the conveyor belt and reduce the number of inspection posts.
2 coking
Temperature measuring robot
Realize fully automatic coke oven flue temperature measurement, and interconnect the measurement results with the control system to achieve energy saving and consumption reduction. The production efficiency of the coke oven is improved, and post-setting is reduced.
3 Laboratory area
1) Raw fuel automatic sampling robot
Realize automatic sampling of raw fuel, and cooperate with pneumatic sample delivery system to realize unmanned sampling of raw fuel.
2) Physical and chemical testing automatic analysis center
Cooperate with the pneumatic sample delivery system and automatic analysis instrument to realize the automatic taking and opening of the sample box, sample transfer, preparation, surface identification, analysis, and filing.
4 Steelmaking area
1) Refining automatic temperature measurement and sampling robot
Realize the height and temperature measurement of molten steel in the refining process, and sampling at fixed points and depths.
2) Fully automatic inspection center for steelmaking
Cooperate with the pneumatic sample delivery system and automatic analysis instrument to realize the automatic taking and opening of the sample box, sample transfer, preparation, surface identification, analysis, and filing.
5 continuous casting area
1) Automatic slag adding robot
Realize automatic slag addition to the crystallizer.
2) Temperature measurement and sampling robot
Realize temperature measurement and sampling of the continuous casting machine.
3) The robot on the receiving side of the ladle
Ladle SN hydraulic tank disassembly and assembly, ladle shroud disassembly and assembly.
6 hot rolling area
Ladle receiving side robot
Ladle SN hydraulic tank disassembly and assembly, ladle shroud disassembly and assembly.
7 cold rolling area
1) Automatic unbundling robot
Automatic identification of the direction of the tape head, the number of straps, automatic tape removal, cutting, and strap collection.
2) Spot welding robot for steel coil inner ring
Automatically find the leading position, compact, and spot-weld the collapsed core, which is beneficial to unmanned crane operation and uncoiling operation in the next process.
3) Automatic labeling robot 
Stick labels on the surface of the inner and outer rings of the steel coil, and cooperate with the scanning system of the crane clamp to realize the automatic verification of the steel coil information.
4) Steel coil sleeve automatic handling robot
Realize automatic classification and stacking of incoming sleeves, automatic matching, transportation, and loading according to the production plan.
5) Continuous withdrawal automatic sampling robot
Realize automatic sorting and stacking of samples, laser coding, and automatic collection of waste boards.
6) Steel coil edge quality inspection robot
By imaging the side of the steel coil and using image analysis technology, the quality judgment of the edge of the steel coil is realized.
7) Fully automatic sample preparation robot in silicon steel performance laboratory
Through the cooperation of multiple robots, laser prototyping machines, and laser coding, the automatic handling, processing, coding, and classification of silicon steel samples are realized.
8) Zinc pot slag removal robot
The zinc slag is automatically removed from the zinc pot, replacing the traditional manual work, and preventing the human body from being harmed by high-temperature, toxic, and harmful areas on site.
8 reservoir area
Unmanned Crane
Realize precise positioning of driving, automatically optimize routes, reduce the labor intensity of driving workers, and improve efficiency.
Robot investment benefit estimation
The use of robots will bring economic and social benefits to iron and steel enterprises. Taking the zinc slag salvage robot in the galvanizing line as an example to estimate the benefit.
At present, the modified zinc slag salvage robot with independent property rights in China is an articulated robot. The main part generally adopts a high-end six-axis six-degree joint that can stably control movement accuracy and is equipped with functions such as safety protection and zinc slag detection. The cost is 1.5 million yuan~ 2 million yuan, the economic benefits expected to be realized after the investment can be estimated from the following aspects (calculated based on Hegang data):
1. Reduce the consumption of zinc ingots
On the basis of automatic zinc slag salvage, reduce the amount of zinc slag salvage by reducing the slag control time and maintaining the optimal slag removal frequency. The zinc slag fishing robot can reduce the amount of zinc slag salvaged by more than 100kg per day, that is, the consumption of zinc ingots in the galvanizing production line can be reduced by 36t/year. Calculated based on the unit price of zinc ingots of 15,000 yuan/t, the expected economic benefits that can be realized by reducing production costs = 15,000 yuan/t×36t/year=540,000 yuan/year.
2. Reduce labor costs
On the basis of automatic zinc slag salvage, industrial robots can be used to replace 2 workers. The salary of each worker is 80,000 yuan/year, and the wage cost of workers can be reduced by 8×2=160,000 yuan/year.
3. Reduce quality objections
On the basis of automatic zinc slag salvage, the impact of manual slag removal on the liquid level of the zinc pool is reduced. At the same time, further study the relationship between the thickness of zinc dross and the surface quality of galvanized sheets, so as to reduce the quality objections of galvanized sheets caused by zinc dross defects. According to the monthly reduction of more than one quality objection, the expected economic benefit that can be generated is 40,000 yuan/month, that is, 480,000 yuan/year.
4. Increase equipment maintenance costs
The use of zinc slag scooping robots requires annual maintenance and maintenance costs of approximately 20,000 yuan per year. At the same time, the cost of daily electricity and public auxiliary consumption required by industrial robots is about 10,000 yuan/year, that is, the increased cost of using robots is 30,000 yuan/year.
After the above calculations, the expected comprehensive economic benefits of the application of the zinc slag salvage robot on the galvanizing line can reach more than 1 million yuan per year.
In terms of social benefits, the application of industrial robots can improve the level of equipment, reduce the labor risk and labor intensity of workers, and save zinc ingot resources.
Conclusion
The application of industrial robots can not only improve production efficiency, reduce production costs, and improve control accuracy and operational stability, but also free workers from working with harsh environments, high labor intensity, and high-risk factors so that workers can devote their energy to higher value-added products and services. With the development of information technology and artificial intelligence in information generation, more and more robots will appear in the production process of steel enterprises. Industrial robots will also bring more benefits to the steel industry.