CN106623709B - Forging process of high-temperature corrosion-resistant flange forging - Google Patents

Abstract

The forging process of the high-temperature corrosion-resistant flange forging piece comprises the steps of adopting a multiple forging process according to the material of the forging piece, putting raw materials into an electric furnace for heating treatment in different time periods, wherein the heating temperature in a first time period is 350-450 ℃; heating to 350-450 ℃ in the second time period and preserving heat; heating to 900-1000 ℃ in a third time period; keeping the temperature of 900-1000 ℃ in the fourth time period; the temperature is increased to 1200-1400 ℃ in the fifth time period; keeping the temperature of 1200-1400 ℃ for 3 hours in the sixth time period, discharging the workpiece from the furnace and forging, and stopping forging when the temperature of the workpiece is reduced from 1200-1400 ℃ to 1100-1200 ℃ in the forging process; and (4) returning the workpiece to the furnace for heating, wherein the heating process is the same as the primary forging heating process, and forging for multiple times. The process effectively ensures the uniformity of the internal and external temperatures of the workpiece, effectively ensures the working heat expansion ratio when the working temperature is accurate to within +/-10, avoids the invasion of elements such as sulfur and phosphorus to the material in the heating process, and improves the service life of the product by more than 30 percent.

Description

Forging process of high-temperature corrosion-resistant flange forging

Technical Field

The invention relates to the technical field of flange forging processing, in particular to a forging process of a high-temperature corrosion-resistant flange forging.

Background

The forged flange is the one with the best mechanical performance in flange products, and the raw material of the forged flange is generally a round bar, and then the forged flange is cut and continuously beaten to eliminate the defects of segregation, looseness and the like in steel ingots. The price and the mechanical property are higher than those of the common cast flange by one grade. The traditional forging method for forging the flange is to put raw materials into a gas producer or a natural gas furnace and heat the raw materials to about 1200-1400 degrees for discharging and forging, the raw materials are forged and formed by an air hammer or a clamping plate hammer at one time, the finished product rate of the forged workpiece is about 70 percent, the metallographic structure analysis is 2-3 grades of forgings, and the sulfur-phosphorus element content in the fuel of the traditional forging process is too high, so that the sulfur-phosphorus element content causes certain damage to the workpiece, the service life of various materials is greatly reduced, and the like

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a forging process of a high-temperature corrosion-resistant flange forging.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a forging process of a high-temperature corrosion-resistant flange forging adopts a multiple forging process according to the material of the forging, and raw materials are put into an electric furnace for heating treatment in different time periods, and the specific process steps are as follows:

(1) primary forging: putting the raw materials into an electric furnace for heating treatment in different time periods, wherein the heating temperature in the first time period is 350-450 ℃, and the heating time is 40 minutes; heating to 350-450 ℃ in the second time period, and keeping the temperature for 1 hour; heating to 900-1000 ℃ in the third time period for 55 minutes; the fourth time period is 900-1000 ℃, and the temperature is kept for 1 hour; in the fifth time period, the temperature is increased to 1200-1400 ℃, and the heating time is 40 minutes; sixthly, keeping the temperature for 3 hours in 1200-1400 ℃, discharging and forging, and stopping forging when the temperature of the workpiece is reduced from 1200-1400 ℃ to 1100-1200 ℃ in the forging process;

(2) forging for multiple times: and (3) returning the workpiece to the furnace for heating, wherein the heating process is the same as the primary forging heating process, and discharging the workpiece from the furnace for forging for multiple times after the workpiece is kept at the temperature of 1200-1400 ℃ for 3 hours.

The process effectively ensures the uniformity of the consistency of the internal temperature and the external temperature of the workpiece, effectively ensures the working thermal expansion ratio when the working temperature is accurate to be within +/-10, avoids the invasion of elements such as sulfur and phosphorus to the material in the heating process, prolongs the service life of the product by more than 30 percent, and effectively ensures the heat resistance and the corrosion resistance of the product in corresponding media in the using process of the product.

Detailed Description

Example 1

A forging process of a high-temperature corrosion-resistant flange forging takes N04400 raw material as an example, adopts a twice forging process, puts the raw material into an electric furnace for heating treatment in different time periods, and comprises the following specific process steps:

(1) primary forging: putting the N04400 raw material into an electric furnace for heating treatment at different time periods, wherein the heating temperature is up to 400 ℃ in the first time period, and the heating time is 40 minutes; heating to 400 ℃ in the second time period, and keeping the temperature for 1 hour; heating to 950 ℃ in a third time period, wherein the heating time is 55 minutes; keeping the temperature for 1 hour at 950 ℃ in the fourth time period; the temperature is increased to 1250 ℃ in the fifth time period, and the heating time is 40 minutes; in the sixth time period of 1250 ℃, keeping the temperature for 3 hours, discharging the workpiece from the furnace and forging the workpiece, and stopping forging when the temperature of the workpiece is reduced from 1250 ℃ to 1150 ℃ in the forging process;

(2) secondary forging: and (3) returning the workpiece to the furnace for heating, wherein the heating process is the same as the primary forging heating process, and discharging the workpiece from the furnace for secondary forging after the workpiece is kept at 1250 ℃ for 3 hours.

The invention avoids the invasion of elements such as sulfur and phosphorus to the material in the heating process, prolongs the service life of the product by more than 30 percent, effectively ensures the heat resistance and the corrosion resistance of the product in corresponding media in the use process of the product, and the mechanical properties of the forged piece meet the corresponding national standards after the forged piece is subjected to the detection of tensile test, impact test, ultrasonic detection, metallographic analysis and the like after being machined. The forged piece is evaluated as a 5-6 grade high standard forged piece after being detected by an authoritative department, and the yield of the product is greatly improved to be close to 100 percent, and the qualification rate of the product leaving the factory is 100 percent.

Example 2

A forging process of a high-temperature corrosion-resistant flange forging takes N10276 as an example, adopts a three-time forging process, puts the raw material into an electric furnace for heating treatment at different time intervals, and comprises the following specific process steps:

(1) primary forging: putting N10276 raw material into an electric furnace for heating treatment at different time periods, wherein the heating temperature is up to 450 ℃ in the first time period, and the heating time is 40 minutes; heating to 450 ℃ in the second time period, and keeping the temperature for 1 hour; the temperature is raised to 1000 ℃ in the third time period, and the heating time is 55 minutes; the fourth time period is 1000 ℃, and the temperature is kept for 1 hour; in the fifth time period, the temperature is increased to 1300 ℃ and the heating time is 40 minutes; in the sixth time period of 1300 ℃, keeping the temperature for 3 hours, discharging from the furnace and forging, and stopping forging when the temperature of the workpiece is reduced from 1300 ℃ to 1200 ℃ in the forging process;

(2) secondary forging: the workpiece is returned to the furnace and heated, the heating process is the same as the primary forging heating process, and the workpiece is taken out of the furnace for secondary forging after being kept at 1300 ℃ for 3 hours;

(3) and (3) forging for the third time: and (3) returning the workpiece to the furnace for heating, wherein the heating process is the same as the primary forging heating process, and discharging the workpiece from the furnace for forging for three times after the workpiece is kept at 1300 ℃.

Claims (1)

1. The forging process of the high-temperature corrosion-resistant flange forging is characterized in that N04400 is used as a raw material, a twice forging process is adopted, the raw material is put into an electric furnace for heating treatment in different time periods, and the specific process steps are as follows:

(1) primary forging: putting the N04400 raw material into an electric furnace for heating treatment at different time periods, wherein the heating temperature is up to 400 ℃ in the first time period, and the heating time is 40 minutes; heating to 400 ℃ in the second time period, and keeping the temperature for 1 hour; heating to 950 ℃ in a third time period, wherein the heating time is 55 minutes; keeping the temperature for 1 hour at 950 ℃ in the fourth time period; the temperature is increased to 1250 ℃ in the fifth time period, and the heating time is 40 minutes; in the sixth time period of 1250 ℃, keeping the temperature for 3 hours, discharging the workpiece from the furnace and forging the workpiece, and stopping forging when the temperature of the workpiece is reduced from 1250 ℃ to 1150 ℃ in the forging process;

(2) secondary forging: and (3) returning the workpiece to the furnace for heating, wherein the heating process is the same as the primary forging heating process, and discharging the workpiece from the furnace for secondary forging after the workpiece is kept at 1250 ℃ for 3 hours.