阅读说明：本技术 一种永不脱落的步进式加热炉装出料悬臂辊及其加工工艺 (Never-falling walking beam roller for charging and discharging of walking beam furnace and processing technology thereof ) 是由 刘荣兵 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种永不脱落的步进式加热炉装出料悬臂辊及其加工工艺,涉及加热炉零部件及其制备技术领域,针对现有的加热炉悬臂辊容易出现辊头易脱落,维修成本高的问题,现提出如下方案,包括以下质量百分比的组分：碳≤0.2%、铬25～30%、镍40～45%、钨0.3～0.5%、钼≥0.5%、铌0.1～0.2%、稀土0.1～0.2%,其余为铁和不可避免的杂质。本发明通过改变合金成分来提高悬臂辊的高温强度和耐温性能,辊轴加工前用球化退火,提高其机械强度,再机械加工成型,焊接后保温处理加工悬臂辊,减少焊接应力,提升了悬臂辊的质量,以倒挂的方式连接后焊接,从结构上改变受力问题,提高悬臂辊的使用寿命,降低维修成本。(The invention discloses a never-falling walking beam type heating furnace charging and discharging cantilever roller and a processing technology thereof, relates to the technical field of heating furnace parts and preparation thereof, and aims to solve the problems that the existing heating furnace cantilever roller is easy to fall off and high in maintenance cost, the following scheme is proposed, and the cantilever roller comprises the following components in percentage by mass: less than or equal to 0.2 percent of carbon, 25-30 percent of chromium, 40-45 percent of nickel, 0.3-0.5 percent of tungsten, more than or equal to 0.5 percent of molybdenum, 0.1-0.2 percent of niobium, 0.1-0.2 percent of rare earth, and the balance of iron and inevitable impurities. According to the invention, the high-temperature strength and the temperature resistance of the cantilever roller are improved by changing alloy components, the mechanical strength of the roller shaft is improved by spheroidizing annealing before processing, then the roller shaft is mechanically processed and molded, and the cantilever roller is processed by heat preservation treatment after welding, so that the welding stress is reduced, the quality of the cantilever roller is improved, the cantilever roller is connected and welded in an inverted hanging manner, the stress problem is changed structurally, the service life of the cantilever roller is prolonged, and the maintenance cost is reduced.)

1. The never-falling charging and discharging cantilever roller of the walking beam furnace is characterized by comprising the following components in percentage by mass: less than or equal to 0.2 percent of carbon, 25-30 percent of chromium, 40-45 percent of nickel, 0.3-0.5 percent of tungsten, more than or equal to 0.5 percent of molybdenum, 0.1-0.2 percent of niobium, 0.1-0.2 percent of rare earth, and the balance of iron and inevitable impurities.

2. The never-falling walking beam furnace charging and discharging cantilever roller of claim 1, which is characterized by comprising the following components in percentage by mass: 0.2% of carbon, 25% of chromium, 45% of nickel, 0.5% of tungsten, 0.6% of molybdenum, 0.2% of niobium, 0.2% of rare earth and the balance of iron and inevitable impurities.

3. The machining process of the charging and discharging cantilever roller of the never-falling walking beam furnace of claim 1, which is characterized by comprising the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

s2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, and connecting the cantilever roller head and the cantilever roller shaft in an inverted hanging manner;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 1-2 hours after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and heat preservation treatment are carried out on the cantilever roller after the welding in the S3.

4. The process for machining the charging and discharging cantilever roller of the never-falling walking beam furnace according to claim 3, wherein in S1, the specific process of spheroidizing annealing is as follows: and (3) placing the machined cantilever roller shaft and the cantilever roller head into a heating furnace, gradually heating to 800-850 ℃, preserving heat for 1-2 hours, cooling to 650-700 ℃, preserving heat for 1-2 hours, and then discharging from the furnace for air cooling.

5. The processing technology of the charging and discharging cantilever roller of the never-falling walking beam furnace of claim 3, wherein in S1, the specific process of the heat treatment is as follows: quenching at 850-880 ℃ for 2-3 h, tempering at 550-580 ℃ for 3-4 h, and cooling alternately by water and air after tempering.

6. The machining process of the charging and discharging cantilever roller of the never-falling walking beam furnace of claim 5, wherein the specific sequence and time of the water-air alternate cooling are as follows: air cooling for 140-150 s, water cooling for 140-150 s, air cooling for 70-80 s, water cooling for 25-30 s, air cooling for 50-60 s, and water cooling for 30-40 s.

7. The process of claim 3, wherein in step S1, the dimensional accuracy and appearance quality of the cantilever roller are tested after the cantilever roller head and the cantilever roller shaft are obtained.

8. The process of claim 3, wherein in step S2, the hanging-over connection mode is as follows: the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and one end with the large diameter is matched with the cantilever roller head.

9. The process for machining the charging and discharging cantilever roller of the never-falling walking beam furnace according to claim 3, wherein the preheating temperature in S3 is 600-800 ℃.

10. The machining process of the charging and discharging cantilever roller of the never-falling walking beam furnace of claim 3, wherein the annealing in S4 is carried out at 580-650 ℃ for 10-15 h.

Technical Field

The invention relates to the technical field of heating furnace parts and preparation thereof, in particular to a never-falling walking beam roller for charging and discharging of a walking beam heating furnace and a processing technology thereof.

Background

The walking beam furnace is a continuous furnace which moves the material blanks forward one by the actions of ascending, advancing, descending and retreating of the furnace bottom or the water-cooled metal beam. The furnace has fixed furnace bottom and step furnace bottom, or fixed beam and step beam. The former is called a walking-beam furnace and the latter is called a walking-beam furnace. The walking beam of a heating furnace for steel rolling is generally composed of water-cooled tubes. The walking beam furnace can heat the blank up and down.

In the steel rolling production process, fill needs the cantilever type roll table to send the material into the heating furnace heating in the heating furnace, current cantilever roll table roller head needs to rely on locating pin and parallel key to fix, in operation, the roller head causes locating pin and parallel key to take place the wearing and tearing fracture easily after receiving crooked blank striking, lead to roller head and roller separation, the roller head falls in the furnace, influence the normal work of heating furnace, even do not strikeed, the condition that drops also can appear after the roller head is used for one to two years mostly, and current cantilever roller junction is little head connection, the time length also can produce the atress inequality and lead to the fracture, the scheduling problem drops, practical life is short, it is high to change troublesome expense, influence work efficiency, maintenance personal's intensity of labour has still been aggravated, cost of maintenance is high, influence the economic benefits of production.

Disclosure of Invention

The invention aims to solve the defects that a roller head of a cantilever roller is easy to separate from a roller shaft due to the connection anti-skidding mode, the maintenance cost is high and the economic benefit is influenced in the prior art, and provides a never-falling walking beam roller for charging and discharging of a stepping heating furnace and a processing technology thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the never-falling charging and discharging cantilever roller of the walking beam furnace comprises the following components in percentage by mass: less than or equal to 0.2 percent of carbon, 25-30 percent of chromium, 40-45 percent of nickel, 0.3-0.5 percent of tungsten, more than or equal to 0.5 percent of molybdenum, 0.1-0.2 percent of niobium, 0.1-0.2 percent of rare earth, and the balance of iron and inevitable impurities.

Preferably, the composition comprises the following components in percentage by mass: 0.2% of carbon, 53.5% of chromium, 45% of nickel, 0.5% of tungsten, 0.6% of molybdenum, 0.2% of niobium, 0.2% of rare earth, and the balance of iron and inevitable impurities.

A processing technology of a permanent non-falling walking beam type heating furnace charging and discharging cantilever roller comprises the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

s2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, and connecting the cantilever roller head and the cantilever roller shaft in an inverted hanging manner;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 1-2 hours after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and heat preservation treatment are carried out on the cantilever roller after the welding in the S3.

Preferably, in S1, the spheroidizing annealing process includes: and (3) placing the machined cantilever roller shaft and the cantilever roller head into a heating furnace, gradually heating to 800-850 ℃, preserving heat for 1-2 hours, cooling to 650-700 ℃, preserving heat for 1-2 hours, and then discharging from the furnace for air cooling.

Preferably, in S1, the specific process of the heat treatment is: quenching at 850-880 ℃ for 2-3 h, tempering at 550-580 ℃ for 3-4 h, and cooling alternately by water and air after tempering.

Preferably, the specific sequence and time of the water-air alternate cooling are as follows: air cooling for 140-150 s, water cooling for 140-150 s, air cooling for 70-80 s, water cooling for 25-30 s, air cooling for 50-60 s, and water cooling for 30-40 s.

Preferably, in S1, after the finished cantilever roller head and cantilever roller shaft are obtained, the dimensional accuracy and appearance quality thereof are checked.

Preferably, in S2, the connection manner of hanging upside down is: the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and one end with the large diameter is matched with the cantilever roller head.

Preferably, in S3, the preheating temperature is 600-800 ℃.

Preferably, the annealing in S4 is carried out at 580-650 ℃ for 10-15 h.

The invention has the beneficial effects that:

1. according to the invention, the content of tungsten in the alloy components of the cantilever roller is reduced, the cracking of the cantilever roller can be reduced, the red stress is improved, the rare earth elements are added to improve the strength, the temperature resistance and the stability of the cantilever roller, and the service life of the cantilever roller is prolonged.

2. During processing, the cantilever roller is subjected to spheroidizing annealing firstly, so that the hardness of the cantilever roller can be reduced firstly, the machinability of the cantilever roller is improved, the mechanical toughness is improved, the subsequent mechanical processing and forming are facilitated, the forming precision is high, the roller shaft is quenched and cooled in a water-air alternating mode in the subsequent heat treatment, quenched martensite can be obtained, the quenching temperature is ensured to be as low as possible, the quenching stress is reduced, the internal quenching crack of the cantilever roller is avoided, and the quality of the cantilever roller is high.

3. When the cantilever roller is processed, the cantilever roller is welded after being connected in an inverted hanging mode, the stress problem is changed structurally, the problems of cracking, breaking and falling caused by uneven stress can not be caused even after long-time working, the service life of the cantilever roller is prolonged, the labor intensity of maintenance personnel is reduced, the maintenance cost is reduced, and the economic benefit is improved.

Drawings

FIG. 1 is a schematic view of the installation of a charging/discharging cantilever roller of a walking beam furnace in the prior art.

FIG. 2 is a schematic view showing the installation of the cantilever roller for charging and discharging the walking beam furnace of the present invention.

Reference numbers in the figures: 1. a cantilever roll shaft; 2. a cantilevered roller head.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example one

The never-falling charging and discharging cantilever roller of the walking beam furnace comprises the following components in percentage by mass: 0.1% of carbon, 25% of chromium, 40% of nickel, 0.3% of tungsten, 0.8% of molybdenum, 0.1% of niobium, 0.1% of rare earth and the balance of iron and inevitable impurities.

The processing technology of the charging and discharging cantilever roller of the never-falling walking beam furnace comprises the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

it is worth to be noted that the specific process of spheroidizing annealing is as follows: placing the machined cantilever roll shaft and the cantilever roll head into a heating furnace, gradually heating to 800 ℃, preserving heat for 1h, then cooling to 650 ℃, preserving heat for 1h, and then discharging from the furnace for air cooling;

it is worth to be noted that the specific process of the heat treatment is as follows: quenching at 850 ℃ for 2h, tempering at 550 ℃ for 3h, and cooling alternately by water and air after tempering, wherein the specific sequence and time are as follows: air cooling 140s, water cooling 140s, air cooling 70s, water cooling 25s, air cooling 50s, water cooling 30s

S2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, wherein the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and the large-diameter end is matched with the cantilever roller head to realize the connection of the cantilever roller head and the cantilever roller shaft, which is shown in figure 2;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 1h after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and preserving heat for the cantilever roller after welding in the S3, wherein annealing is carried out for 15h at the temperature of 580 ℃, and stress is consolidated and eliminated.

Example two

The never-falling charging and discharging cantilever roller of the walking beam furnace comprises the following components in percentage by mass: 0.15% of carbon, 26% of chromium, 42% of nickel, 0.4% of tungsten, 1% of molybdenum, 0.15% of niobium, 0.15% of rare earth and the balance of iron and inevitable impurities.

The processing technology of the charging and discharging cantilever roller of the never-falling walking beam furnace comprises the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

it is worth to be noted that the specific process of spheroidizing annealing is as follows: placing the machined cantilever roller shaft and the cantilever roller head into a heating furnace, gradually heating to 820 ℃, preserving heat for 1.5h, then cooling to 670 ℃, preserving heat for 1.5h, and then discharging from the furnace for air cooling;

it is worth to be noted that the specific process of the heat treatment is as follows: quenching at 860 ℃ for 2h, tempering at 560 ℃ for 3h, and cooling alternately by water and air after tempering, wherein the specific sequence and time are as follows: air cooling 140s, water cooling 140s, air cooling 70s, water cooling 25s, air cooling 50s, water cooling 30s

S2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, wherein the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and the large-diameter end is matched with the cantilever roller head to realize the connection of the cantilever roller head and the cantilever roller shaft, which is shown in figure 2;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 1.5 hours after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and preserving heat for the cantilever roller after welding in the S3, wherein annealing is carried out at the temperature of 600 ℃ for 12h during annealing, and stress is consolidated and eliminated.

EXAMPLE III

The never-falling charging and discharging cantilever roller of the walking beam furnace comprises the following components in percentage by mass: 0.2% of carbon, 28% of chromium, 48% of nickel, 0.5% of tungsten, 0.6% of molybdenum, 0.2% of niobium, 0.2% of rare earth and the balance of iron and inevitable impurities.

The processing technology of the charging and discharging cantilever roller of the never-falling walking beam furnace comprises the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

it is worth to be noted that the specific process of spheroidizing annealing is as follows: placing the machined cantilever roller shaft and the cantilever roller head into a heating furnace, gradually heating to 840 ℃, preserving heat for 1.5h, cooling to 680 ℃, preserving heat for 1.5h, and then discharging from the furnace for air cooling;

it is worth to be noted that the specific process of the heat treatment is as follows: quenching at 870 ℃ for 2.5h, tempering at 570 ℃ for 3.5h, and cooling alternately by water and air after tempering, wherein the specific sequence and time are as follows: air cooling 145s, water cooling 145s, air cooling 70s, water cooling 30s, air cooling 50s, water cooling 30s

S2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, wherein the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and the large-diameter end is matched with the cantilever roller head to realize the connection of the cantilever roller head and the cantilever roller shaft, which is shown in figure 2;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 2 hours after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and preserving heat for the cantilever roller after welding in the S3, wherein annealing is carried out for 12 hours at the temperature of 620 ℃ during annealing, and stress is consolidated and eliminated.

Example four

The never-falling charging and discharging cantilever roller of the walking beam furnace comprises the following components in percentage by mass: 0.2% of carbon, 30% of chromium, 45% of nickel, 0.5% of tungsten, 1.5% of molybdenum, 0.2% of niobium, 0.2% of rare earth and the balance of iron and inevitable impurities.

The processing technology of the charging and discharging cantilever roller of the never-falling walking beam furnace comprises the following steps:

s1, obtaining raw materials with corresponding weight according to mass percentage, smelting, refining, casting, spheroidizing annealing, machining and forming and quenching and tempering the raw materials to obtain a blank cantilever roller head and a cantilever roller shaft, and carrying out finish machining and roller shaft quenching and tempering on the blank cantilever roller head and the cantilever roller shaft to obtain a finished cantilever roller head and a finished cantilever roller shaft;

it is worth to be noted that the specific process of spheroidizing annealing is as follows: placing the machined cantilever roll shaft and the cantilever roll head into a heating furnace, gradually heating to 850 ℃, preserving heat for 1h, then cooling to 700 ℃, preserving heat for 2h, and then discharging from the furnace for air cooling;

it is worth to be noted that the specific process of the heat treatment is as follows: quenching at 880 ℃ for 3h, tempering at 580 ℃ for 4h, and cooling alternately by water and air after tempering, wherein the specific sequence and time are as follows: air cooling 150s, water cooling 140s, air cooling 80s, water cooling 25s, air cooling 50s, water cooling 30s

S2, cleaning the joint of the cantilever roller head and the cantilever roller shaft prepared in the S1, wherein the diameter of the cantilever roller shaft is gradually reduced from one end to the other end, and the large-diameter end is matched with the cantilever roller head to realize the connection of the cantilever roller head and the cantilever roller shaft, which is shown in figure 2;

s3, preheating the joint of the cantilever roller head and the cantilever roller shaft, preserving heat for 2 hours after preheating at 620 ℃, and finishing one-time welding on the joint under the condition of continuous heat preservation to obtain the cantilever roller;

and S4, annealing and preserving heat for the cantilever roller after welding in the S3, wherein annealing is carried out at the temperature of 650 ℃ for 10 hours during annealing, and stress is consolidated and eliminated.

The cantilever rollers welded in the four groups of embodiments are marked as 1, 2, 3 and 4, cantilever roller shafts and cantilever roller heads in the market are purchased at the same time, big-head fish cantilever rollers of the cantilever roller shafts are welded as comparative examples and marked as a mark 5, and the component details of five groups of products are shown in the following table:

by comparing the components, the invention reduces the content of tungsten, increases the rare earth elements and reduces the addition of silicon.

Detecting the products with the 5 marks according to a test method for Shore hardness detection in GB/T13313-2008; impact test: respectively fixing five groups of products, and continuously striking the cantilever roller head with the same force from the direction parallel to the axis until the cantilever roller head falls off; the results of both tests are as follows:

the above table shows that the hardness of the cantilever roller with the reference numbers 1, 2, 3 and 4 is obviously superior to that of the cantilever roller with the reference number 5, and the hardness of the cantilever roller is obviously improved by changing the alloy components of the cantilever roller, so that the service life of the cantilever roller can be prolonged.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.