A method and system for ordering a ship steel plate specification uniform type

Abstract

The application provides a ship steel plate order specification unification method, comprising the following steps: S1, collecting ship types under construction and steel plate order data of each ship type; S2, dividing the steel plate order data into multiple thickness intervals, and in each thickness interval, dividing the steel plate order data into multiple steel plate specifications according to steel plate materials, and calculating tonnage proportions of each steel plate specification; S3, selecting steel plate specifications with tonnage proportions greater than a preset threshold, and setting a steel plate order weight threshold, and combining the selected steel plate specifications in the steel plate order weight threshold to obtain multiple new steel plate order specifications; and S4, calculating steel plate utilization rates under each new steel plate order specification, and selecting a new steel plate order specification with the largest steel plate utilization rate as a final steel plate order specification, wherein the steel plate utilization rate is a ratio of a design weight of a steel plate to an order weight. The application standardizes steel plate order specifications, is beneficial to standardized manufacturing of steel materials, and solves the problem of long steel material procurement cycle.

Description

Technical Field

[0001] This application relates to the field of ship steel plate design technology, and more specifically, to a method and system for standardizing ship steel plate ordering specifications. Background Technology

[0002] Controlling steel plate costs is primarily limited by the types and quantities of steel procured. Currently, the shipbuilding industry procures diverse and non-standardized steel. For example, an 86,000 cubic meter liquefied gas carrier might require over 2,500 different steel plate specifications, 16 times the design specifications. While this may improve steel utilization to some extent, the diverse range of steel specifications not only hinders standardized or large-scale steelmaking in steel mills but also creates numerous inconveniences for shipyards. These include difficulties in ordering small-tonnage steel plates, long procurement cycles, and challenges in stacking and handling steel plates, leading to slow steel plate consumption and extended site occupancy periods. Furthermore, the initial design investment required for diverse steel plate specifications makes improving steel utilization through customization ultimately counterproductive and not a sustainable development model. Summary of the Invention

[0003] The purpose of this application is to provide a method and system for standardizing the ordering specifications of ship steel plates, which solves the problems of low overall economic efficiency caused by the diversification of steel plate ordering specifications, long ordering cycles, and difficulties in material turnover under the prior art.

[0004] Firstly, a standardized method for ordering ship steel plates is provided, including:

[0005] S1. Organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and ordering quantity.

[0006] S2. Divide the steel plate ordering data into multiple thickness ranges. Within each thickness range, for the steel plate material, divide the steel plate ordering data into multiple steel plate specifications and calculate the tonnage percentage of each steel plate specification.

[0007] S3. Select steel plate specifications with a tonnage ratio greater than the preset threshold, and set a critical value for steel plate order weight. Within the critical value for steel plate order weight, merge the selected steel plate specifications by width to obtain multiple new steel plate order specifications.

[0008] S4. Calculate the steel plate utilization rate for each new steel plate ordering specification, and select the new steel plate ordering specification with the highest steel plate utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the order weight.

[0009] In one implementation, step S3, merging the widths of the selected steel plate specifications, includes merging the widths of the selected steel plate specifications using a step-size method.

[0010] In one implementation, the step-size method for merging the widths of selected steel plate specifications includes:

[0011] The width of the steel plate of the selected steel plate specification with the largest order quantity is used as the benchmark. The width of the steel plate specification that exceeds the benchmark is reduced by a step value and merged into the benchmark. The width of the steel plate specification that is less than the benchmark is increased by a step value and merged into the benchmark. The step value is a multiple of 5.

[0012] In one implementation, step S2, dividing the steel plate ordering data into multiple thickness ranges, includes:

[0013] The steel plate ordering data is divided into three thickness ranges: 6mm to 8mm (inclusive), 8mm to 50mm (exclusive), and greater than or equal to 50mm.

[0014] In one implementation, in step S3, selecting steel plate specifications with a tonnage percentage greater than a preset threshold includes selecting steel plate specifications with a tonnage percentage greater than 1%, where the tonnage percentage is the ratio of the order weight of each steel plate specification to the total order weight.

[0015] In one implementation, in S3, the critical value of the steel plate order weight is estimated based on the ship design weight, including a estimation coefficient that comprehensively considers the steel plate ordering cost, design input, ordering cycle and material turnover cost, and the critical value of the steel plate order weight is determined by combining the steel plate order weight and the estimation coefficient.

[0016] In one embodiment, in step S2, the steel plate material includes conventional steel and special steel. The conventional steel includes carbon steel, which is classified into low-carbon steel, medium-carbon steel, and high-carbon steel according to its carbon content. The special steel includes low-temperature steel plate, crack-resistant steel, and stainless steel.

[0017] According to a second aspect of this application, a standardized system for ordering ship steel plates is also provided, comprising:

[0018] The steel plate ordering data module is used to organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and order quantity.

[0019] The steel plate specification classification module is used to divide steel plate ordering data into multiple thickness ranges. Within each thickness range, based on the steel plate material, the steel plate ordering data is divided into multiple steel plate specifications, and the tonnage percentage of each steel plate specification is calculated.

[0020] The steel plate specification merging module is used to select steel plate specifications whose tonnage ratio is greater than a preset threshold, and to set a steel plate order weight threshold. Within the steel plate order weight threshold, the selected steel plate specifications are merged by width to obtain multiple new steel plate order specifications.

[0021] The module for determining steel plate ordering specifications is used to calculate the steel plate utilization rate under each new steel plate ordering specification, and to select the new steel plate ordering specification with the highest steel plate utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the order weight.

[0022] The beneficial effects of the standardized method and system for ordering ship steel plates in this application are as follows:

[0023] Standardizing steel plate ordering specifications facilitates standardized manufacturing at steel mills, resolves the company's long steel procurement cycle, and allows for more effective site planning and utilization, thereby shortening the construction cycle. It also addresses the overall low economic efficiency caused by the diverse steel plate ordering specifications, long ordering cycles, and difficulties in material handling under existing technologies. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating a method for standardizing the ordering specifications of ship steel plates according to an embodiment of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] Shipbuilding costs in the shipbuilding industry include material costs, equipment costs, equipment and spare parts costs, total man-hours and labor costs, and production-specific expenses. Material costs include steel, welding materials, paint, cables, auxiliary materials, and timber. Steel costs constitute the largest proportion of raw material costs in the shipbuilding industry, ranging from 20% to 30% depending on the ship type. In terms of order backlog, my country's shipbuilding industry currently focuses on bulk carriers, container ships, liquefied gas carriers, and oil tankers. All four ship types are major steel consumers. Statistics show that a 76,000-ton bulk carrier uses 11,000 tons of steel, while a 400,000-ton ore carrier uses 50,000 tons. Affected by the overall rise in commodity prices, the price of marine steel plates also increased rapidly in 2020. Although there was a slight pullback at the end of the year, it continued to rise after the beginning of 2022.

[0029] Therefore, controlling steel costs is crucial. Steel includes steel plates, profiles, and pipes. Among these, steel plates, a specialty of the shipbuilding industry, have their cost control directly impacting the overall economic efficiency of a vessel. Steel plate cost control is primarily limited by the types and quantities of steel procured. Currently, the shipbuilding industry procures diverse and non-standardized steel. For example, an 86,000 cubic meter liquefied gas carrier might require over 2,500 different steel plate specifications, 16 times the design specifications. While this may improve steel utilization to some extent, the diverse range of steel specifications not only hinders standardized or large-scale steelmaking in steel mills but also creates numerous inconveniences for shipyards. These include difficulties in ordering smaller steel plates, long procurement cycles, and slow steel plate consumption due to stacking and handling, leading to extended site occupancy periods. Furthermore, the initial design investment required for diverse steel plate specifications makes this approach of increasing steel utilization through customization ultimately counterproductive and not a sustainable development model. Based on the above considerations, the inventors proposed a standardized approach to ordering ship steel plates, which is described in detail below:

[0030] Firstly, this application provides a method for standardizing the specifications of ship steel plates for ordering. Figure 1 This is a flowchart illustrating a method for standardizing ship steel plate ordering specifications according to an embodiment of this application. See also... Figure 1 ,include:

[0031] S1. Organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and ordering quantity.

[0032] S2. Divide the steel plate ordering data into multiple thickness ranges. Within each thickness range, for the steel plate material, divide the steel plate ordering data into multiple steel plate specifications and calculate the tonnage percentage of each steel plate specification.

[0033] S3. Select steel plate specifications with a tonnage ratio greater than the preset threshold, and set a critical value for steel plate order weight. Within the critical value for steel plate order weight, merge the selected steel plate specifications by width to obtain multiple new steel plate order specifications.

[0034] S4. Calculate the steel plate utilization rate for each new steel plate ordering specification, and select the new steel plate ordering specification with the highest utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the ordered weight, i.e., steel utilization rate = (design weight / ordered weight) * 100%. It should be noted that the relationship between the number of new steel plate ordering specifications and the steel utilization rate is as follows: as the steel plate specification step size increases, the number of specifications decreases accordingly, the steel plate weight increases accordingly, and the final steel utilization rate decreases. Conversely, as the steel plate specification step size decreases, the number of specifications decreases accordingly, the steel plate weight decreases accordingly, and the final steel utilization rate increases. In the specific design process, it is necessary to specifically calculate the steel plate utilization rate to select the new steel plate ordering specification with the highest utilization rate as the final steel plate ordering specification. In other words, the steel plate utilization rate is maximized while reducing the number of steel plate ordering specifications.

[0035] In the aforementioned implementation process, based on the standardization of steel plate procurement types and specifications, a new steel plate ordering specification is selected as the standard for subsequent ship type orders by using a critical steel plate ordering weight value. This facilitates standardized manufacturing at steel mills, solves the problem of long steel procurement cycles for ships, and allows for more effective planning and rational utilization of construction sites, thereby shortening the construction cycle. It also addresses the overall low economic efficiency caused by various inconveniences in existing technologies, such as diverse steel plate ordering specifications, long ordering cycles, and difficulties in material handling.

[0036] In one implementation, step S3 involves merging the widths of selected steel plate specifications using a step-size method. Specifically, the width of the steel plate specification with the largest order quantity is selected as a baseline. The widths of selected steel plate specifications exceeding the baseline are then merged with the baseline by subtracting a step-size value. Similarly, the widths of selected steel plate specifications smaller than the baseline are merged with the baseline by adding a step-size value. The step-size value is a multiple of 5. That is, a step-size value G is set, which is a multiple of 5. For width merging, the original specifications are merged from fewer to more, i.e., the fewer specifications plus the step-size value are moved towards the more numerous specifications, resulting in the types, quantities, and weights of specifications with a given thickness and material width. This includes considering the order quantities of different specifications and merging them towards the specifications with the largest order quantities. The weight also does not exceed a preset order weight threshold, thus reducing the number of steel plate specifications. This achieves standardized steel plate procurement types and reduces the number of steel plate specifications procured.

[0037] To facilitate better standardization of steel specifications, in one embodiment, S2, the steel plate ordering data is divided into multiple thickness ranges, including dividing the steel plate ordering data into three thickness ranges: 6mm to 8mm (inclusive), 8mm to 50mm (exclusive), and greater than or equal to 50mm.

[0038] To further improve economic efficiency, the steel plate specifications are optimized based on the tonnage ratio of the overall steel plate specifications. In one implementation scheme, in S3, selecting steel plate specifications with a tonnage ratio greater than a preset threshold includes selecting steel plate specifications with a tonnage ratio greater than 1%, wherein the tonnage ratio is the ratio of the order weight of each steel plate specification to the total order weight.

[0039] In one implementation scheme, in S3, the critical weight for steel plate ordering is estimated based on the ship's design weight. This estimation involves comprehensively considering steel plate ordering costs, design inputs, ordering cycles, and material handling costs to establish an estimation coefficient. The critical weight for steel plate ordering is determined by combining the actual order weight with this estimation coefficient. For example, if the ship's design weight is approximately 50,000 tons, and an estimation coefficient of 1.01 is established, the steel plate ordering weight would be 5 * 1.01 = 50,500 tons. The closer the critical weight for steel is to the design weight, the higher the utilization rate, and the lower the ordering cost, regardless of steel price factors.

[0040] In one embodiment, in S2, the steel plate material includes conventional steel and special steel. The conventional steel includes carbon steel, which is classified into low-carbon steel, medium-carbon steel and high-carbon steel according to its carbon content. The special steel includes low-temperature steel plate, crack-resistant steel and stainless steel.

[0041] Secondly, this application also provides a standardized system for ordering ship steel plates, including:

[0042] The steel plate ordering data module is used to organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and order quantity.

[0043] The steel plate specification classification module is used to divide steel plate ordering data into multiple thickness ranges. Within each thickness range, based on the steel plate material, the steel plate ordering data is divided into multiple steel plate specifications, and the tonnage percentage of each steel plate specification is calculated.

[0044] The steel plate specification merging module is used to select steel plate specifications whose tonnage ratio is greater than a preset threshold, and to set a steel plate order weight threshold. Within the steel plate order weight threshold, the selected steel plate specifications are merged by width to obtain multiple new steel plate order specifications.

[0045] The module for determining steel plate ordering specifications is used to calculate the steel plate utilization rate under each new steel plate ordering specification, and to select the new steel plate ordering specification with the highest steel plate utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the order weight.

[0046] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for standardizing the ordering specifications of ship steel plates, characterized in that, include: S1. Organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and ordering quantity. S2. Divide the steel plate ordering data into multiple thickness ranges. Within each thickness range, for the steel plate material, divide the steel plate ordering data into multiple steel plate specifications and calculate the tonnage percentage of each steel plate specification. S3. Select steel plate specifications with a tonnage ratio greater than the preset threshold, and set a critical value for steel plate order weight. Within the critical value for steel plate order weight, merge the selected steel plate specifications by width to obtain multiple new steel plate order specifications. S4. Calculate the steel plate utilization rate for each new steel plate ordering specification, and select the new steel plate ordering specification with the highest steel plate utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the order weight. In S3, the steel plate width merging of the selected steel plate specifications includes merging the steel plate width of the selected steel plate specifications using the step size method. The step-size method for merging the width of selected steel plate specifications includes: selecting the width of the steel plate specification with the largest order quantity as a benchmark; subtracting the step-size value from the width of the selected steel plate specifications that exceed the benchmark and merging them towards the benchmark; adding the step-size value to the width of the selected steel plate specifications that are less than the benchmark and merging them towards the benchmark, wherein the step-size value is a multiple of 5. In S2, dividing the steel plate ordering data into multiple thickness ranges includes dividing the steel plate ordering data into three thickness ranges: [6mm, 8mm], (8mm, 50mm) and greater than or equal to 50mm. In step S3, selecting steel plate specifications with a tonnage percentage greater than a preset threshold includes selecting steel plate specifications with a tonnage percentage greater than 1%, where the tonnage percentage is the ratio of the order weight of each steel plate specification to the total order weight.

2. The method for standardizing ship steel plate ordering specifications according to claim 1, characterized in that, In S3, the critical value of the steel plate order weight is estimated based on the ship design weight, including a estimation coefficient that comprehensively considers the steel plate ordering cost, design investment, ordering cycle and material turnover cost, and the critical value of the steel plate order weight is determined by combining the steel plate order weight and the estimation coefficient.

3. The method for standardizing ship steel plate ordering specifications according to claim 1, characterized in that, In S2, the steel plate material includes conventional steel and special steel. The conventional steel includes carbon steel, which is classified into low-carbon steel, medium-carbon steel and high-carbon steel according to its carbon content. The special steel includes low-temperature steel plate, crack-resistant steel and stainless steel.

4. A system for standardizing ship steel plate ordering specifications using the method described in claim 1, characterized in that, include: The steel plate ordering data module is used to organize the steel plate ordering data for each type of ship under construction. The steel plate ordering data includes the classification society, ordering specifications, ordering weight and design weight. The ordering specifications include steel plate length, steel plate width, steel plate thickness, steel plate material and order quantity. The steel plate specification classification module is used to divide steel plate ordering data into multiple thickness ranges. Within each thickness range, based on the steel plate material, the steel plate ordering data is divided into multiple steel plate specifications, and the tonnage percentage of each steel plate specification is calculated. The steel plate specification merging module is used to select steel plate specifications whose tonnage ratio is greater than a preset threshold, and to set a steel plate order weight threshold. Within the steel plate order weight threshold, the selected steel plate specifications are merged by width to obtain multiple new steel plate order specifications. The module for determining steel plate ordering specifications is used to calculate the steel plate utilization rate under each new steel plate ordering specification, and to select the new steel plate ordering specification with the highest steel plate utilization rate as the final steel plate ordering specification. The steel plate utilization rate is the ratio of the design weight of the steel plate to the order weight.

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