阅读说明：本技术 一种04Cr13Ni5Mo水电用超级马氏体不锈钢中厚板退火工艺 (Annealing process of 04Cr13Ni5Mo hydroelectric super martensitic stainless steel medium plate ) 是由 李照国 潘吉祥 纪显彬 徐斌 王珂 武小强 于 2020-09-27 设计创作，主要内容包括：本发明公开了一种04Cr13Ni5Mo水电用马氏体不锈钢中厚板连续退火酸洗工艺,属于不锈钢热处理工艺技术领域,所述退火工艺采用如下顺序的处理工艺：先直接酸洗、正火处理、回火处理,后退火板酸洗。本发明通过对使工艺路线调整、参数优化,减少钢板酸洗次数,大幅度提高产品表面质量、合格率及生产效率。本发明专利是淘汰前期落后工艺,采用辊底式连续退火炉连续退火,有效保证了生产的连续性和产品质量的稳定性。(The invention discloses a continuous annealing and pickling process for a 04Cr13Ni5Mo hydroelectric martensitic stainless steel medium plate, belonging to the technical field of stainless steel heat treatment processes, wherein the annealing process adopts the following sequential treatment processes: firstly, directly pickling, normalizing, tempering and pickling the annealed plate. The invention reduces the acid washing times of the steel plate by adjusting the process route and optimizing the parameters, and greatly improves the surface quality, the qualification rate and the production efficiency of the product. The invention relates to a method for continuously annealing a steel plate by a roller-hearth continuous annealing furnace, which is used for eliminating early-stage lagging processes and effectively ensuring the production continuity and the stability of product quality.)

1. The annealing process of the 04Cr13Ni5Mo hydroelectric super martensitic stainless steel medium plate is characterized in that the annealing process adopts the following sequential treatment processes: firstly, directly pickling, normalizing, tempering and pickling the annealed plate.

2. The annealing process of the 04Cr13Ni5Mo super martensitic stainless steel medium plate for hydropower according to claim 1, wherein the annealing process is carried out on a straight stainless steel medium plateThe pickling comprises the following specific steps: the 04Cr13Ni5Mo super martensitic stainless steel medium and heavy plate is cut into a fixed length, is not annealed and is directly subjected to acid pickling, the shot blasting current is 65-75A, the throwing speed is 2000-: HF solution of 55-70g/L, HNO of 120-150g/L₃The temperature of the solution is 60-70 ℃, and the pickling speed is 5-8 m/min.

3. The annealing process of the 04Cr13Ni5Mo super martensitic stainless steel medium plate for hydropower according to claim 1, wherein the thickness of the 04Cr13Ni5Mo super martensitic stainless steel medium plate is 6-100 mm.

4. The annealing process of the 04Cr13Ni5Mo super martensitic stainless steel medium plate for hydropower according to claim 1, wherein the normalizing treatment comprises the following specific steps: normalizing the pickled 04Cr13Ni5Mo super martensitic stainless steel medium plate at 1050-.

5. The annealing process of the 04Cr13Ni5Mo super martensitic stainless steel medium plate for hydropower according to claim 1, wherein the tempering treatment comprises the following specific steps: the normalized 04Cr13Ni5Mo super martensitic stainless steel medium plate is tempered at the temperature of 650 plus 700 ℃, the heating coefficient is 1.0min/mm, the heat preservation coefficient is 2.0min/mm, and air cooling is carried out after the tempering treatment.

6. The annealing process of the 04Cr13Ni5Mo super martensitic stainless steel medium plate for water and electricity according to claim 1, wherein the annealing plate pickling comprises the following specific steps: performing acid cleaning on the annealed 04Cr13Ni5Mo super martensitic stainless steel medium and thick plate for the second time, wherein the shot blasting current is 65-75A, the throwing speed is 2000-2300r/min, and a mixed acid pickling process is adopted, wherein the HF solution is 55-70g/L, and the HNO solution is 120-150g/L₃Pickling the solution at 60-70 deg.C5-8m/min。

Technical Field

The invention belongs to the technical field of stainless steel heat treatment processes, and particularly relates to a continuous annealing and pickling process of a 04Cr13Ni5Mo hydroelectric martensitic stainless steel medium plate.

Background

04Cr13Ni5Mo super martensitic stainless steel as the most commonly used hydroelectric stainless steel, which reduces carbon (ω c) on the basis of Cr13 martensitic stainless steel<0.03% or<0.025%) and sulfur (. omega.c)<0.01% or<0.005%), high strength, good toughness and welding performance of Ni (4-6.5%) and Mo (2.5%) and containing CO₂And H₂The corrosion resistance in the medium of S is greatly improved. The anti-leakage valve is mainly applied to flow passage components such as blades, wear plates, lining plates, leakage-stopping ring materials and embedded parts of hydraulic engineering. The high-strength high-toughness high-hardness composite material has high strength, high toughness, good welding performance and high surface hardness, and can meet the requirement that a flow passage component of hydraulic engineering bears the erosion of silt for a long time.

The thickness requirement of the steel grade in the hydropower industry is generally 6-100mm, and the most important requirement is that the steel grade has higher performance requirement, which is mainly reflected in meeting the mechanical property of the industry standard and good plate flatness.

At present, the annealing process of the steel grade comprises normalizing, tempering and pickling, the annealing process is carried out in a trolley type box type resistance furnace, and the defects of low production efficiency and small furnace charging quantity are overcome; the temperature of the side close to the furnace door is not uniform, so that the structure of the side of the plate close to the furnace door is inconsistent with the structure of the middle part of the plate, and the performance is unstable; meanwhile, the cooling speed of the head, the tail and the middle of the plate after the plate is discharged from the furnace is different in the cooling process, so that the defects of plate-type end warping, deformation and the like are caused; after normalizing and tempering, the oxide scale is very thick, the final pickling process cannot be qualified by one-time pickling, and the pickling needs to be carried out for multiple times, so that the efficiency is low.

Disclosure of Invention

The invention aims to: aiming at the existing problems, the invention provides an annealing process of a 04Cr13Ni5Mo hydroelectric super martensitic stainless steel medium plate.

The technical scheme adopted by the invention is as follows:

an annealing process of a 04Cr13Ni5Mo hydroelectric super martensitic stainless steel medium plate adopts the following sequential treatment processes: firstly, directly pickling, normalizing, tempering and pickling the annealed plate.

Preferably, the direct pickling comprises the following specific steps: the 04Cr13Ni5Mo super martensitic stainless steel medium and heavy plate is cut into a fixed length, is not annealed and is directly subjected to acid pickling, the shot blasting current is 65-75A, the throwing speed is 2000-: HF solution of 55-70g/L, HNO of 120-150g/L₃The temperature of the solution is 60-70 ℃, and the pickling speed is 5-8 m/min. The main purpose is to clean the hot-rolled oxide skin by acid for one time.

Preferably, the thickness of the 04Cr13Ni5Mo super martensitic stainless steel medium plate is 6-100 mm.

Preferably, the normalizing treatment comprises the following specific steps: normalizing the pickled 04Cr13Ni5Mo super martensitic stainless steel medium plate at 1050-.

Preferably, the tempering treatment comprises the following specific steps: the normalized 04Cr13Ni5Mo super martensitic stainless steel medium plate is tempered at the temperature of 650 plus 700 ℃, the heating coefficient is 1.0min/mm, the heat preservation coefficient is 2.0min/mm, and air cooling is carried out after the tempering treatment.

Preferably, the annealing plate pickling comprises the following specific steps: performing acid cleaning on the annealed 04Cr13Ni5Mo super martensitic stainless steel medium and thick plate for the second time, wherein the shot blasting current is 65-75A, the throwing speed is 2000-2300r/min, and a mixed acid pickling process is adopted, wherein the HF solution is 55-70g/L, and the HNO solution is 120-150g/L₃The solution is washed at 60-70 deg.C and acid washing speed of 5-8 m/min. The main purpose is to remove the surface oxide scale after acid washing.

The invention reduces the acid washing times of the steel plate by adjusting the process route and optimizing the parameters, and greatly improves the surface quality, the qualification rate and the production efficiency of the product. The invention relates to a method for continuously annealing a steel plate by a roller-hearth continuous annealing furnace, which is used for eliminating early-stage lagging processes and effectively ensuring the production continuity and the stability of product quality.

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the invention, the super martensitic stainless steel medium plate is directly pickled, so that the problem that pickling is difficult due to internal oxidation of elements with strong affinity with O, such as Cr, Si, Ni and the like in a steel plate after direct normalizing and tempering of an existing oxide scale of the super martensitic stainless steel medium plate is avoided, the surface requirement can be met only by pickling for 4 times after the original annealing, the two-time pickling and one-time pickling are reduced to be qualified, and the efficiency is improved by 1 time;

(2) the invention can realize continuous charging by adopting the roller-hearth continuous annealing furnace, and the production efficiency is improved by 4-8 times; the atmosphere in the roller-hearth continuous annealing furnace is stable and uniform, the medium plate slowly runs in the furnace, the head and the tail are uniformly heated, and the structure performance is stable.

(3) The invention adopts the water mist cooling of the section 1 of the quenching machine behind the continuous annealing furnace with higher normalizing temperature, the cooling environment is uniform, the cooling is rapidly carried out to 500 ℃, the subsequent cooling section roller is protected, and the flat plate shape is obtained.

Drawings

FIG. 1 shows a technical structure (tempered cord) according to the present invention.

Detailed Description

The present invention will be described in further detail in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1

Step one, acid washing: 10 blocks of 04Cr13Ni5Mo hot-rolled super martensitic stainless steel medium and thick plates with the thickness of 60mm are cut to length without annealing process,directly pickling in a continuous pickling line, continuously entering the pickling line, performing shot blasting at a current of 65-75A and a throwing speed of 2000-: 55-70g/L of HNO₃Solution at 120-150g/L, temperature: the pickling speed is 5-8m/min at 60-70 ℃. And cleaning the hot-rolled oxide skin by acid washing at one time.

Step two, continuously charging 10 pickled 04Cr13Ni5Mo steel plates at the inlet of a continuous annealing furnace, and carrying out normalizing treatment at 1050-: and (3) swinging the steel plate in the annealing furnace along with the roller way within 120min, slowly discharging the normalized steel plate out of an outlet furnace door of the annealing furnace along with the roller way, entering a quenching machine, uniformly cooling by adopting water mist, cooling to 500 ℃, and then air-cooling to room temperature.

And step three, continuously charging the normalized 10 pieces of 04Cr13Ni5Mo steel plates from the inlet of the annealing furnace, tempering at the temperature of 650 plus 700 ℃, heating for 60min, keeping the temperature for 120min, slowly discharging the tempered steel plates out of the outlet furnace door of the annealing furnace along with the roller table after the time requirement is met, putting the quenching machine into use, and performing post air cooling after the tempering.

Step four, carrying out acid pickling on the 04Cr13Ni5Mo steel plate subjected to normalizing and tempering for the second time, wherein the shot blasting current is 65-75A, the throwing speed is 2000-2300r/min, and the process of mixed acid pickling is adopted, wherein the HF solution: 55-70g/L of HNO₃Solution at 120-150g/L, temperature: the pickling speed is 5-8m/min at 60-70 ℃. The surface after acid washing is very uniform, the head and tail properties of the steel plate are almost not different, and the requirements of national standard GB/T4237-.

Example 2

Step one, acid washing: 10 pieces of 04Cr13Ni5Mo hot-rolled super martensitic stainless steel medium and thick plates with the thickness of 20mm are cut into fixed length, an annealing process is not carried out, the plates are directly pickled in a continuous pickling line and continuously enter the pickling line, the shot blasting current is 65-75A, the throwing speed is 2000-2300r/min, and a mixed acid pickling process is adopted, wherein the HF solution comprises the following steps: 55-70g/L of HNO₃Solution at 120-150g/L, temperature: pickling speed is 5-8m/min at 60-70 ℃; and cleaning the hot-rolled oxide skin by acid washing at one time.

Step two, continuously charging 10 pickled 04Cr13Ni5Mo steel plates at the inlet of a continuous annealing furnace, and carrying out normalizing treatment at 1050-: and (4) swinging the steel plate in the annealing furnace along with the roller way in the furnace for 40min, slowly discharging the normalized steel plate out of an outlet furnace door of the annealing furnace along with the roller way, entering a quenching machine, uniformly cooling by adopting water mist, cooling to 500 ℃, and then air-cooling to room temperature.

Continuously charging 10 normalized 04Cr13Ni5Mo steel plates from an inlet of an annealing furnace, carrying out tempering treatment at the temperature of 650 plus 700 ℃, heating for 20min, and keeping the temperature for 40min, wherein after the time requirement is met, the tempered steel plates slowly exit from an outlet furnace door of the annealing furnace along with a roller way, a quenching machine is not put into use, and after the tempering treatment, air cooling is carried out;

step four, carrying out acid pickling on the 04Cr13Ni5Mo steel plate subjected to normalizing and tempering for the second time, wherein the shot blasting current is 65-75A, the throwing speed is 2000-2300r/min, and the process of mixed acid pickling is adopted, wherein the HF solution: 55-70g/L of HNO₃Solution at 120-150g/L, temperature: pickling speed is 5-8m/min at 60-70 ℃; the surface after acid washing is very uniform, the head and tail properties of the steel plate are almost not different, and the requirements of national standard GB/T4237-.

The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.