阅读说明：本技术 超大外圆法兰加工工艺 (Machining process for oversized outer circular flange ) 是由 费新海 费爱华 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种超大外圆法兰加工工艺,属于法兰加工领域,其技术方案要点是准备钢锭,钢锭经过退火处理、初步正火处理、再次正火处理、淬火处理、回火处理,用压机将长条状钢锭弯曲弧形成为原始件,各个原始件放置平台上拼接成一个完整的圆,之后在原始件的焊接坡口进行焊接形成一个完整的法兰,本发明的优点在于摆脱传统超大型碾环机对于法兰加工尺寸的限制,降低法兰的生产成本。(The invention discloses a processing technology of an oversized outer-circle flange, which belongs to the field of flange processing, and adopts the technical scheme that steel ingots are prepared, the steel ingots are subjected to annealing treatment, primary normalizing treatment, secondary normalizing treatment, quenching treatment and tempering treatment, a press is used for bending and curving a strip-shaped steel ingot into original pieces, all the original pieces are spliced into a complete circle on a placing platform, and then welding is carried out on a welding groove of the original pieces to form a complete flange.)

1. The processing technology of the oversized outer circular flange is characterized by comprising the following steps:

s1: preparing a plurality of steel ingot rough blanks, and pressing the steel ingot rough blanks into long strips;

s2: annealing the steel ingot at 905-915 ℃, then preserving heat, and finally air-cooling to room temperature;

s3: carrying out primary normalizing treatment on the steel ingot, wherein the normalizing temperature is 855-865 ℃, then preserving heat,

finally, cooling the water to room temperature;

s4: normalizing the steel ingot again at 875-885 deg.C, and keeping the temperature,

finally, cooling the water to room temperature;

s5: quenching the steel ingot at 735-745 ℃, then preserving heat, and finally cooling the oil to room temperature;

s6: tempering the steel ingot at the tempering temperature of 230 ℃, then preserving heat, and finally cooling the steel ingot to room temperature;

s7: bending the strip-shaped steel ingot into an original piece by adopting a press, wherein the radian of the original piece is 360 degrees/designed piece number;

s8: machining welding grooves at the left end and the right end of an original piece;

s9: splicing all the original parts on the original part placing platforms into a complete circle, and then welding the original parts on the welding grooves to form a complete flange;

s10: machining the welding position of the flange;

s11: and electroplating the flange.

2. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S2, the heat preservation time is 1h30min-2h, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer when the size of the steel ingot is larger.

3. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S3, the heat preservation time is 45min-1h, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer when the size of the steel ingot is larger.

4. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S4, the heat preservation time is 50min to 55min, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

5. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S5, the heat preservation time is 20min to 30min, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

6. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S6, the heat preservation time is 30min to 40min, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

7. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: in step S8, a welding groove is provided on each of the inner and outer sides of the end of the original, and the depth of the welding groove is half of the thickness of the original.

8. The machining process of the extra-large outer circular flange according to claim 7, characterized in that: the corresponding central angle range of the welding groove is 10-12 degrees.

9. The processing technology of the extra large outer circular flange according to claim 1, characterized in that: the flange comprises the following chemical elements in percentage by mass: c: 0.033-1.97%; cr: 12.11 to 12.52 percent; mo: 0.71-0.87; v: 0.57-0.62%; ni: 0.26 to 0.64 percent; the remainder being Fe.

Technical Field

The invention relates to the field of flange machining, in particular to a machining process of an oversized outer circular flange.

Background

A Flange (Flange), also known as a Flange collar or Flange. The flange is a part for connecting the shafts and is used for connecting pipe ends; there are also flanges on the inlet and outlet of the device for connection between two devices. The conventional flange is generally manufactured into an annular flange in the existing ring rolling mill, but the size of the manufactured flange is limited by the maximum rolling outer diameter of the ring rolling mill, only a few manufacturers with ultra-large ring rolling mills with the diameter of more than 1.5m can produce the ultra-large flange at present, the market of the ultra-large flange is monopolized, the cost of the ultra-large flange is high, and the requirement of industrial development cannot be met.

Disclosure of Invention

The invention aims to provide a processing technology of an oversized outer-circle flange, which has the advantages of getting rid of the limitation of the traditional oversized ring rolling mill on the processing size of the flange and reducing the production cost of the flange.

The technical purpose of the invention is realized by the following technical scheme:

a processing technology of an oversized outer circular flange comprises the following steps:

s1: preparing a plurality of steel ingot rough blanks, and pressing the steel ingot rough blanks into long strips;

s2: annealing the steel ingot at 905-915 ℃, then preserving heat, and finally air-cooling to room temperature;

s3: carrying out primary normalizing treatment on the steel ingot, wherein the normalizing temperature is 855-865 ℃, then preserving heat, and finally cooling to room temperature by water;

s4: normalizing the steel ingot again at the normalizing temperature of 875-;

s5: quenching the steel ingot at 735-745 ℃, then preserving heat, and finally cooling the oil to room temperature;

s6: tempering the steel ingot at the tempering temperature of 230 ℃, then preserving heat, and finally cooling the steel ingot to room temperature;

s7: bending the strip-shaped steel ingot into an original piece by adopting a press, wherein the radian of the original piece is 360 degrees/designed piece number;

s8: machining welding grooves at the left end and the right end of an original piece;

s9: splicing all the original parts on the original part placing platforms into a complete circle, and then welding the original parts on the welding grooves to form a complete flange;

s10: machining the welding position of the flange;

s11: and electroplating the flange.

Further, in step S2, the heat preservation time is 1h30min-2h, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

Further, in step S3, the heat preservation time is 45min to 1h, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

Further, in step S4, the heat preservation time is 50min to 55min, and is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

Further, in step S5, the heat preservation time is 20min to 30min, and is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

Further, in step S6, the heat preservation time is 30min to 40min, the heat preservation time is determined according to the size of the steel ingot, and the heat preservation time is longer as the size of the steel ingot is larger.

Further, in step S6, a welding groove is provided on each of the inner and outer sides of the end of the original, and the depth of the welding groove is half of the thickness of the original.

Further, the corresponding central angle range of the welding groove is 10-12 degrees.

Further, the mass percentages of all chemical elements in the flange are as follows: c: 0.033-1.97%; cr: 12.11 to 12.52 percent; mo: 0.71-0.87; v: 0.57-0.62%; ni: 0.26 to 0.64 percent; the remainder being Fe.

In conclusion, the invention has the following beneficial effects:

1. informing to prepare high-quality original pieces, welding a plurality of arc-shaped original pieces into a complete ultra-large flange without using a large ring rolling mill, reducing the requirements on equipment and reducing the production cost of the flange;

2. through heat treatment, crystal grains are refined, the structure is improved, the metal hardness is reduced, the subsequent bending processing is facilitated, the internal stress and the brittleness of the metal are reduced, and the rejection rate of the subsequent machined parts is reduced;

3. every tip of primitive is provided with two welding grooves, firmly welds two primitives into a whole through the welding groove, and the welding groove design guarantees to be completely melted through at the welding department, improves welding quality.

Drawings

FIG. 1 is a schematic view of the steps of a process for machining an oversized outer circular flange;

fig. 2 is a schematic view of flange welding.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example 1: a processing technology of an oversized outer circular flange is shown in figure 1 and comprises the following steps:

s1: preparing a plurality of steel ingot rough blanks, and pressing the steel ingot rough blanks into long strips for later use by adopting a ring rolling mill. The steel ingot, namely the mass percent of each chemical element in the flanges manufactured subsequently, is as follows: c: 0.033-1.97%; cr: 12.11 to 12.52 percent; mo: 0.71-0.87; v: 0.57-0.62%; ni: 0.26 to 0.64 percent; the remainder being Fe. Cr can improve the hardenability of the steel, the Cr content exceeds 12 percent, the steel has good corrosion resistance, the Cr content is ensured to be less than 13 percent, and metal is controlled in a gamma or gamma + alpha phase region so as to generate martensite in the subsequent heat treatment; mo is a forming element for strengthening carbide, the wear resistance of the steel is improved, and the content of Mo is more than 0.5 percent, so that the tempering brittleness caused by other elements can be effectively inhibited; v can form high-hardness carbide, so that the wear resistance is improved; ni is mainly used to improve hardenability of steel.

S2: annealing the steel ingot at 905 ℃, then preserving heat, wherein the heat preservation time of the steel ingot is 1h30min-2h, the heat preservation time is determined according to the size of the steel ingot, the heat preservation time is longer when the size of the steel ingot is larger, and finally, air cooling is carried out to room temperature. The temperature of the steel ingot entering the furnace is controlled below 200 ℃, the steel ingot is heated to a specified temperature at a heating speed of 110 ℃/h, and the tapping temperature of the steel ingot is controlled below 280 ℃ after the heating is finished. In the annealing process, pearlite transformation occurs in the steel ingot, and internal stress in the steel ingot is eliminated.

S3: and carrying out primary normalizing treatment on the steel ingot, wherein the normalizing temperature is 855 ℃, then carrying out heat preservation for 45min-1h, wherein the heat preservation time is determined according to the size of the steel ingot, the heat preservation time is longer when the size of the steel ingot is larger, and finally, carrying out water cooling to room temperature. The temperature of the steel ingot entering the furnace is controlled below 190 ℃, the steel ingot is heated to a specified temperature at a heating speed of 150 ℃/h, and the tapping temperature of the steel ingot is controlled below 230 ℃ after the heating is finished. The normalizing process diffuses at a high rate for the crystal structure, and the coarse grains are further refined.

S4: normalizing the steel ingot again at 875 ℃, and then preserving heat for 50-55 min, wherein the heat preservation time is determined according to the size of the steel ingot, the larger the size of the steel ingot is, the longer the heat preservation time is, and finally, cooling the steel ingot to room temperature by water. The temperature of the steel ingot entering the furnace is controlled below 190 ℃, the steel ingot is heated to a specified temperature at a heating speed of 150 ℃/h, and the tapping temperature of the steel ingot is controlled below 230 ℃ after the heating is finished. And refining the grains again through secondary normalizing.

S5: quenching the steel ingot, wherein the quenching temperature is 735 ℃, then preserving heat for 20-30 min, the heat preservation time is determined according to the size of the steel ingot, the heat preservation time is longer when the size of the steel ingot is larger, and finally, the oil is cooled to the room temperature. The temperature of the steel ingot entering the furnace is controlled below 200 ℃, the steel ingot is heated to a specified temperature at a heating speed of 180 ℃/h, and the tapping temperature of the steel ingot is controlled below 200 ℃ after the heating is finished. The quenching is to obtain martensite structure, mechanical properties of high metal products or parts, and the most important is to improve the wear resistance and prolong the service life of the flange.

S6: tempering the steel ingot at the tempering temperature of 230 ℃, then preserving heat for 30-40 min, wherein the heat preservation time is determined according to the size of the steel ingot, the heat preservation time is longer when the size of the steel ingot is larger, and finally, the oil is cooled to the room temperature. The temperature of the ingot entering the furnace is controlled below 170 ℃, the ingot is heated to a specified temperature at a heating speed of 160 ℃/h, and after the heating is finished, the tapping temperature of the steel ingot is controlled below 250 ℃. The tempering aims at reducing the internal stress and brittleness of the steel ingot and facilitating the subsequent machining of the steel ingot.

S7: the long-strip-shaped steel ingot is bent into an original piece by adopting a press, and the radian of the original piece is 360 degrees/designed piece number. As shown in fig. 2, in the present embodiment, the number of the designed pieces is 4, and the central angle of the original piece is 90 °.

S8: as shown in fig. 2, welding grooves are machined at the left end and the right end of the original piece, the inner side and the outer side of the end of the original piece are respectively provided with one welding groove, and the depth of the welding groove is half of the thickness of the original piece. The corresponding central angle range of the welding groove is 10-12 degrees.

S9: as shown in fig. 2, the worker first draws the appearance of the design flange on the platform, and splices the originals on the platform into a complete circle. And then welding the welding groove of the original piece to form a complete flange. The corresponding central angle range of the welding groove is 10-12 degrees.

S10: and machining the welding position of the flange, and polishing burrs at the welding position.

S11: and electroplating the flange.

Example 2: the difference from example 1 is that:

s2: the annealing temperature was 910 ℃.

S3: the preliminary normalizing temperature was 860 ℃.

S4: the normalizing temperature is 880 ℃ again.

S5: the quenching temperature was 740 ℃.

Example 3: the difference from example 1 is that:

s2: the annealing temperature was 915 ℃.

S3: the preliminary normalizing temperature was 865 ℃.

S4: the normalizing temperature is 885 ℃.

S5: the quenching temperature is 745 ℃.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.