阅读说明：本技术 一种热轧q235a、q235b、ss400集约柔性化生产方法 (Intensive flexible production method for hot rolling Q235A, Q235B and SS400 ) 是由 郭靖 于 2020-11-24 设计创作，主要内容包括：本发明公开了一种热轧Q235A、Q235B、SS400集约柔性化生产方法,以适应当前客户需求的多样性,首先从钢铁产品标准着手,考虑具有相同或相近力学性能钢铁牌号的归并,利用钢铁材料的细晶化、复相化等强化机理,通过对轧制与冷却工艺的调整实现具有减量化成分坯料的柔性化升降级轧制,充分发挥钢铁材料性能的内在潜力,实现“一钢多能”的集约化生产目的,为实际生产组织、节能降本取到了良好的应用效果。(The invention discloses an intensive flexible production method of hot rolling Q235A, Q235B and SS400, which is used for adapting to the diversity of current customer requirements, and is based on the standard of steel products, considers the mergence of steel grades with the same or similar mechanical properties, utilizes the strengthening mechanisms of grain refining, multiphase and the like of steel materials, realizes flexible up-down rolling of blanks with reduced components by adjusting rolling and cooling processes, fully exerts the internal potential of the performance of the steel materials, realizes the intensive production purpose of one-steel multiple energy, and obtains good application effects for actual production organization, energy saving and cost reduction.)

1. A method for intensively and flexibly producing hot rolled Q235A, Q235B and SS400 is characterized by comprising the following steps:

s1, designing components

S1.1, collecting production data of the early stage Q235A, the early stage Q235B and the early stage SS400 in a factory, analyzing actual production data by using a process capability index Cpk, and explaining the control capability of the components of the three in production;

s1.2, reasonably adjusting the components of the three components in the control capability of the mechanical properties through the calculation of Cpk, the average value and the qualification rate;

s1.3, the components and performance of Q235A, Q235B and SS400 are measured and calculated to be relatively close to each other, the components are merged by combining theoretical support, and the components are designed and unified into the components with the mass percentages shown in the following table:

s2, implementation process and process

Designing the components in the step S1.3 as GE components in an ERP system for control to carry out continuous casting production, automatically distinguishing three steel types according to different GK code systems of the three steel types after the slab is produced, and preparing for later-stage steel type division rolling; the rolling processes of the three are respectively shown in the following table:

Technical Field

The invention relates to the technical field of ferrous metallurgy and steel rolling processes, in particular to an intensive flexible production method for hot rolling Q235A, Q235B and SS 400.

Background

Because of the limitation of traditional concept, industry habit and standard, the adjustment of mechanical property is mainly realized by changing the components, so that materials with similar properties adopt different chemical components, and the steel types are various; on one hand, the method is unfavorable for steel-making organization production, and increases the consumption of human resources; on the other hand, the strengthening mechanisms of grain refining, multiphase transformation and the like of the steel material cannot be fully utilized, and the inherent potential of the performance of the steel material cannot be fully exerted. In order to adapt to the diversity of current customer requirements, firstly starting from the standard of steel products, considering the merging of steel grades with the same or similar mechanical properties, realizing the flexible up-down rolling of blanks with reduced components by adjusting the rolling and cooling processes, realizing the intensive production purpose of one-steel multiple energy, and having important theoretical and practical significance.

Disclosure of Invention

The invention aims to provide an intensive flexible production method for hot rolling Q235A, Q235B and SS400, which fully exerts the advantages of GA, GK and GE component control of steel grades according to the design concept of an ERP system of a rare earth steel plate plant, successfully realizes the effective fusion of Q235A, Q235B and SS400, adopts one component design for the three merged steel grades, realizes the flexible rolling of Q235A, Q235B and SS400 by applying TMCP (thermo-mechanical control) technology, namely the adjustment of rolling and cooling processes, verifies the feasibility of the intensive production technology from the experimental point of view, greatly simplifies the smelting difficulty and effectively controls the fluctuation of steelmaking components.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention relates to an intensive flexible production method for hot rolling Q235A, Q235B and SS400, which comprises the following steps:

s1, designing components

S1.1, collecting production data of the early stage Q235A, the early stage Q235B and the early stage SS400 in a factory, analyzing actual production data by using a process capability index Cpk, and explaining the control capability of the components of the three in production;

s1.2, reasonably adjusting the components of the three components in the control capability of the mechanical properties through the calculation of Cpk, the average value and the qualification rate;

s1.3, the components and performance of Q235A, Q235B and SS400 are measured and calculated to be relatively close to each other, the components are merged by combining theoretical support, and the components are designed and unified into the components with the mass percentages shown in the following table:

s2, implementation process and process

Designing the components in the step S1.3 as GE components in an ERP system for control to carry out continuous casting production, automatically distinguishing three steel types according to different GK code systems of the three steel types after the slab is produced, and preparing for later-stage steel type division rolling; the rolling processes of the three are respectively shown in the following table:

compared with the prior art, the invention has the beneficial technical effects that:

the invention adopts intensive chemical component blanks, produces products with different strength grades through a flexible rolling strategy, and finally achieves the aim of one steel with multiple functions. Therefore, the operation and management of steel making and continuous casting can be simplified, the continuous and stable production of the steel making and continuous casting process is facilitated, the steel making, continuous casting, slab warehouse and heating furnace can be conveniently connected, the management is simplified, the complexity is reduced, and the requirement of large-scale production of enterprises is met. Meanwhile, the technology has obvious advantages that products with different performance levels are produced by optimizing the production processes related to hot rolling, cooling after rolling and heat treatment to meet different use requirements of users, and the performance potential of steel products is exerted to the maximum extent.

Drawings

The invention is further illustrated in the following description with reference to the drawings.

FIG. 1 is a flow chart of a conventional production method;

FIG. 2 is a flow chart of the intensive flexible production of the present invention.

Detailed Description

1. Theoretical support

The quantitative relation between the yield strength and the grain size can be known according to Hall-Petch formula

In the formula, d is the average diameter of crystal grains, Be 0 is an action term of other strengthening modes, and k is a steel grade constant. As shown in the formula (1), when the grain size is controlled from 15 to 20 μm to 3 to 5 μm, the yield strength of the material can be doubled. In the development of fine grain plain carbon steel, a product with a yield strength of 400MPa has been successfully produced using the composition of Q235B.

Merging analysis of Q235A, Q235B and SS400

The enterprise also has specific standards relative to the country in actual production, and the standards are generally within the range of national standards, as shown in tables 1-3. As can be seen from the table below, the compositions of the three tapping marks corresponding to Q235B and SS400 are different from each other but have small differences, mainly the differences in the contents of C and Mn.

Table 1Q 235A chemical composition units: is based on

Table 2Q 235B chemical composition units: is based on

Table 3Q 235B chemical composition units: is based on

3. Detailed description of the invention

3.1 ingredient design implementation Process

The production data of the three previous stages in the factory are collected, the actual production data are analyzed by using the process capability index Cpk, the control capability of the three components in the production is illustrated, and the calculation results are shown in tables 4-6.

TABLE 4 indices of chemical composition of Q235A

TABLE 5 indices of chemical composition Q235B

TABLE 6 SS400 chemical composition index

Analyzing the above Cpk values, the control capability of C, Si and Mn of Q235A is sufficient, the control level of S, Alt and Als is general, the control level of P is poor, and the control of the latter four should be strengthened; the control level of each element component of Q235B and SS400 is high, the control capability is sufficient, and the qualification rate is high; when the contents of C, Si and Mn are required to be adjusted during merging, the steelmaking control capacities of the three can be met; since Q235A requires relatively high ranges and target values of P and S components and is relatively weak in controllability, it is considered that the requirements can be relaxed appropriately without affecting the performance, and the ranges and target values of P and Si of Q235B and SS400 are different from the former but have excessive controllability, and therefore, they can be realized relatively easily when adjusting them. Meanwhile, for the Cpk value in the table larger than 2.0, the difficulty of controlling the Cpk value can be considered to be reduced so as to save the cost.

3.2 Performance design implementation Process

The control capability of the three on the mechanical property is shown in tables 7-9 through the calculation of Cpk, the average value and the qualification rate; it can be seen that they all have a surplus in their ability to control yield strength, while the control of tensile strength and elongation is relatively poor, and the ability is general, so it is considered appropriate to reduce the carbon content of Q235A and increase the manganese content of Q235B.

TABLE 7Q 235A Performance index

TABLE 8Q 235B Performance index

TABLE 9 SS400 Performance index

3.3 component design determination

According to the calculation of the components and performance of Q235A, Q235B and SS400 of 3.1 and 3.2, the components and the performance are relatively close to each other, and the components can be merged into a B01 steel by combining with theoretical support, and the component design is shown in Table 10.

Table 10B 01 compositional design units: is based on

3.4 Process implementation

The components are designed to be used as GE components in an ERP system for control to carry out continuous casting production, three steel grades are automatically distinguished according to different GK code systems of the three components after a slab is produced, and preparation is provided for later-stage steel grade division rolling. The rolling processes of the three are shown in tables 11-12.

TABLE 11Q 235A/Q235B Rolling Process

TABLE 12 SS400 Rolling Process

The properties of the three rolled steel sheets according to the above processes are shown in tables 13-14.

TABLE 13 mechanical performance indices of Q235A/Q235B

TABLE 14 SS400 mechanical Properties index

The performance control for the three was calculated by calculating Cpk, average and yield as shown in the table above. It can be seen that they have relatively high control over yield strength, tensile strength and elongation, and are highly capable. The qualification rate completely meets the production requirement.

Products with different strength levels are produced by adopting intensive chemical component blanks through a flexible rolling strategy, and the purpose of one-steel multiple functions is finally realized. Therefore, the operation and management of steel making and continuous casting can be simplified, the continuous and stable production of the steel making and continuous casting process is facilitated, the steel making, continuous casting, slab warehouse and heating furnace can be conveniently connected, the management is simplified, the complexity is reduced, and the requirement of large-scale production of enterprises is met. Meanwhile, the technology has obvious advantages that products with different performance levels are produced by optimizing the production processes related to hot rolling, cooling after rolling and heat treatment to meet different use requirements of users, and the performance potential of steel products is exerted to the maximum extent.

According to the design concept of an ERP system of a rare earth steel plate factory, the invention fully exerts the advantages of GA, GK and GE component control of steel grades, successfully realizes the effective fusion of Q235A, Q235B and SS400, adopts one component design for the three merged steel grades, realizes the flexible rolling of Q235A, Q235B and SS400 by applying TMCP (thermo-mechanical control) technology, namely the adjustment of rolling and cooling processes, verifies the feasibility of intensive production technology from the experimental point of view, and compares the graph in FIG. 1 with the graph in FIG. 2 to know that the flexible rolling technology greatly simplifies the difficulty of smelting and effectively controls the fluctuation of steelmaking components

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.