Production method of high-speed drawing welding wire with mark of ER70S-6BX

Abstract

The invention discloses a production method of a high-speed drawing welding wire with the mark of ER70S-6BX. The production method is mainly optimized as follows: (1) the content range of two harmful elements P and S is strictly controlled, and P is less than or equal to 0.025%; (2) revising the number of trimming circles of the head and the tail, trimming the head for 9-11 circles, and trimming the tail for 14-16 circles; and (3) the roller way speed of the Stelmor cooling line cooling process is re-formulated. The invention aims to provide the production method of the high-speed drawing welding wire with the mark of ER70S-6BX, so that the ER70S-6BX can be used for drawing products with the diameter phi of 1.0 mm and the diameter phi of 0.8 mm, the tensile property of the ER70S-6BX is controlled to be 510 MPa or below, and the area reduction rate is kept to be 80% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of rolling, and in particular relates to a production method of a high-speed drawn welding wire with a brand of ER70S-6BX. Background Art

[0002] ER70S-6 welding wire steel is a kind of steel wire widely used in gas shielded welding, especially suitable for carbon dioxide (CO 2 ) Gas shielded manual welding, submerged arc welding, semi-continuous welding and automatic welding. It has been widely used in pressure vessels, electric power, automobiles and various machinery manufacturing industries due to its good welding performance, high weld performance and arc stability. With the development of welding automation, the demand for gas shielded welding wire has greatly increased, which has promoted the production and development of ER70S-6 welding wire steel. Our welding wire products with the brand number of ER70S-6 have always been our flagship products, but we have not carried out product upgrades for a long time. It has been difficult to adapt to the requirements of downstream welding wire processing companies for high-speed full-continuous drawing of φ1.0mm and φ0.8mm products. Downstream welding wire companies now use Baosteel products to only draw φ1.2mm welding wire. And since last year, old welding wire customers have also reduced their order quantities.

[0003] In order to meet the downstream high-speed production and drawing of φ1.0mm and φ0.8mm products, a brand ER70S-6BX was developed, and the performance of Baosteel parent material φ6.5mm specification welding wire ER70S-6 product was targeted for upgrading. In order to ensure its excellent drawing performance, a production method for high-speed drawing of fine specification welding wire must be studied, so that ER70S-6BX can draw φ1.0mm and φ0.8mm products, and the metallographic structure is ferrite + pearlite + a small amount of bainite. Summary of the invention

[0004] The purpose of the present invention is to provide a production method for high-speed drawing welding wire with the brand ER70S-6BX, so that ER70S-6BX can draw φ1.0mm and φ0.8mm products, control the tensile performance of ER70S-6BX below 510MPa, and maintain the area reduction rate above 80%.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The invention discloses a production method of a high-speed drawn welding wire with a brand of ER70S-6BX, and the main production steps are: molten iron pretreatment → converter → LF furnace refining → continuous casting → billet acceptance → transportation → heating furnace charging → billet heating → high-pressure water descaling → roughing mill rolling → intermediate mill rolling → finishing mill rolling → sizing mill rolling → controlled water cooling → diameter gauge → laying head → Stelmor roller cooling → coiling → trimming, surface quality inspection → packaging → weighing → labeling → storage; the characteristics are:

[0007] (1) Strictly control the content range of two harmful elements, P and S, P ≤ 0.025%; S: ≤ 0.025

[0008] (2) The number of trimming circles for the head and tail was revised to 9-11 circles for the head and 14-16 circles for the tail;

[0009] (3) Reformulate the roller speed of the cooling process of the Stelmo cooling line:

[0010]

[0011] Furthermore, the chemical composition of the ER70S-6BX high-speed drawing welding wire by mass percentage is: C: 0.06-0.09%; Si: 0.80-0.90%; Mn: 1.60-1.80%; P≤0.025%; S: ≤0.025%; the remainder is Fe and a small amount of impurity elements.

[0012] Furthermore, after the implementation of the new roller cooling speed, the performance stability was greatly improved.

[0013] Furthermore, after adjustment, the tensile properties of the product are stabilized at 480MPa-510MPa.

[0014] Furthermore, after adjustment, the shrinkage rate of the product is stabilized at more than 80%.

[0015] Furthermore, after adjustment, the metallographic structure of the product is ferrite + pearlite + a small amount of bainite.

[0016] Furthermore, the head is changed to trimming 10 turns, and the tail is changed to trimming 15 turns.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are:

[0018] After adjustment, the tensile properties of the product are stabilized at 480MPa-510MPa, and the surface shrinkage rate is stabilized at more than 80%, providing a good foundation for subsequent deep processing.

[0019] The specific example data obtained through the above measures show that the performance of the welding wire ER70S-6BX is improved. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to specific embodiments.

[0021] The P and S control ranges of the ER70S-6BX welding wire steel in each embodiment are shown in Table 1:

[0022] Table 1 Control range of P and S elements (%)

[0023] Example No. P S Compliance with internal control Example 1 0.007 0.007 yes Example 2 0.012 0.008 yes Example 3 0.015 0.006 yes Example 4 0.008 0.006 yes Example 5 0.010 0.008 yes

[0024] The quality of raw materials of products has been greatly improved by implementing strict control of the two elements P and S;

[0025] The reformulated Stelmo cooling process:

[0026] The roller speed was re-established based on the existing equipment capacity as shown in Table 2:

[0027] Table 2 Roller speed

[0028]

[0029] After the implementation of the new roller cooling speed, the performance stability has been greatly improved.

[0030] The improvement of the stability of the mechanical properties of the product is taken as an example of the same circle difference:

[0031] Table 3

[0032]

[0033] After adjustment, the tensile strength of the product is stabilized at 480MPa-510MPa, and the shrinkage rate is stabilized at 80%, which provides a good foundation for subsequent deep processing.

[0034] The specific example data obtained through the above measures show that the performance of the welding wire ER70S-6BX is improved.

[0035] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A production method of high-speed drawn welding wire with a grade of ER70S-6BX, the main production steps of which are: molten iron pretreatment → converter → LF furnace refining → continuous casting → billet acceptance → transfer → heating furnace charging → billet heating → high-pressure water descaling → roughing mill rolling → intermediate mill rolling → finishing mill rolling → sizing mill rolling → controlled water cooling → diameter gauge → laying head → Stelmor roller cooling → coiling → trimming, surface quality inspection → packaging → weighing → listing → storage; the characteristics are: (1) Strictly control the content range of two harmful elements, P and S, P ≤ 0.025%; S: ≤ 0.025 (2) The number of trimming circles for the head and tail was revised to 9-11 circles for the head and 14-16 circles for the tail; (3) Reformulate the roller speed of the cooling process of the Stelmo cooling line:

2. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: The chemical composition of the ER70S-6BX high-speed drawing welding wire is as follows: C: 0.06-0.09%; Si: 0.80-0.90%; Mn: 1.60-1.80%; P≤0.025%; S:≤0.025%; the remainder is Fe and a small amount of impurity elements.

3. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: After the implementation of the new roller cooling speed, the performance stability has been greatly improved.

4. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: After adjustment, the tensile properties of the product are stabilized at 480MPa-510MPa.

5. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: After adjustment, the product shrinkage rate is stabilized at more than 80%.

6. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: After adjustment, the metallographic structure of the product is ferrite + pearlite + a small amount of bainite.

7. The method for producing the ER70S-6BX high-speed drawn welding wire according to claim 1, characterized in that: Change the head to trim 10 turns and the tail to trim 15 turns.

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