Search

CN-122007305-A - G115 large-specification continuous casting round billet forging method

CN122007305ACN 122007305 ACN122007305 ACN 122007305ACN-122007305-A

Abstract

A method for forging a G115 large-size continuous casting round billet comprises the following steps of 1) carrying out high-temperature homogenization treatment on the G115 large-size continuous casting round billet, heating the round billet to 600-650 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 5-8 hours, continuously heating the round billet to 1000-1050 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 3-5 hours, continuously heating the round billet to 1240-1280 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 30-50 hours, stopping heating, heating the round billet after the furnace temperature is reduced to 800-1000 ℃, and then heating the round billet to a forging heating temperature, 2) carrying out forging heating on the round billet at the speed of 50-100 ℃ per hour, preserving heat for 5-10 hours, 3) forging the round billet on a quick forging machine, and obtaining a forging piece at the forging temperature of 1100-1150 ℃ and the final forging temperature of 850-900 ℃, 4) carrying out annealing heat treatment, and 5) carrying out tempering heat treatment.

Inventors

  • ZHAO HAIPING
  • TANG ZAIXING
  • SUN QIANG
  • JIN CHENG
  • ZHAO XIN
  • ZHAO HAIYAN
  • SUN CHUANFEI

Assignees

  • 宝武特种冶金有限公司
  • 宝武特冶(马鞍山)高金科技有限公司

Dates

Publication Date
20260512
Application Date
20260303

Claims (5)

  1. 1. The forging method of the G115 large-specification continuous casting round billet is characterized by comprising the following steps of: 1) High temperature homogenization treatment Heating the G115 large-size continuous casting round billet to 600-650 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 5-8 hours, continuously heating to 1000-1050 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 3-5 hours, continuously heating to 1240-1280 ℃ at the speed of 50-80 ℃ per hour, preserving heat for 30-50 hours, stopping heating, and heating to forging heating temperature after the furnace temperature is reduced to 800-1000 ℃, wherein the G115 large-size continuous casting round billet has the specification of phi 600-1200 mm and the weight of 10-17 tons, and preferably spraying an anti-oxidation coating on the surface of the continuous casting round billet before heating; 2) Forging heating Heating the continuous casting round billet to 1160-1200 ℃ at the speed of 50-100 ℃ per hour, and keeping the temperature for 5-10 hours; 3) Forging Forging the continuous casting round billet on a rapid forging machine, wherein the forging temperature is 1100-1150 ℃, the final forging temperature is 850-900 ℃, forging is performed at least three times of upsetting and three times of drawing to form a forging piece, the height delta H under each upsetting is less than or equal to H0/2, the upsetting ratio is 2.3-2.7, the forging ratio of the wide anvil strong pressing forging method drawing is 2.7-3.2, the pressing deformation of each anvil is 20-25%, the forging pressing rate is 0.001s -1 ~0.05s -1 , the initial pressing rate is controlled to be 50-70 mm each time, then the pressing rate is gradually increased to 100-120 mm, during the forging process, when the surface temperature is lower than 900 ℃, the forging is performed, the hot forging is performed, the heat preservation time is more than or equal to 3 hours under 1160-1200 ℃, and the forging temperature is controlled to 850-950 ℃ during the final hot forging; 4) Annealing heat treatment The annealing temperature is 770-790 ℃, the annealing time is 15-30 h, after the annealing is finished, cooling to below 200 ℃ along with the furnace, discharging, and air cooling to room temperature; 5) Tempering heat treatment The quenching and tempering heat treatment comprises quenching and tempering, wherein the quenching temperature is 1060-1080 ℃, water cooling is carried out, the tempering temperature is 770-790 ℃, and air cooling is carried out.
  2. 2. The G115 large scale continuous casting round billet forging method as recited in claim 1, wherein in step 3), the upper and lower anvils are preheated before the start of forging, and the anvil surface preheating temperature is not lower than 500 ℃.
  3. 3. The G115 large scale continuous casting round billet forging method according to claim 1, wherein in step 4), annealing is performed within 2 hours of completion of forging.
  4. 4. The method for forging the large-size G115 continuous casting round billet according to claim 1, wherein in the step 5), the forging is subjected to tempering heat treatment, the temperature is raised to 900-1000 ℃ at a rate of 50-80 ℃ per hour, heat preservation is carried out for at least 2 hours, the temperature is raised to 1060-1080 ℃ at a rate of 50-80 ℃ per hour, quenching is carried out, the quenching heat preservation time is 5-10 hours, water cooling is carried out to room temperature, the temperature is raised to 770-790 ℃ at a rate of 50-80 ℃ per hour, tempering is carried out, the tempering heat preservation time is 7-12 hours, and air cooling is carried out to room temperature.
  5. 5. The G115 large scale continuous casting round billet forging method as recited in claim 1, wherein the G115 large scale continuous casting round billet has a composition weight percentage of ：C 0.060～0.100%,Si≤0.55%,Mn 0.27～0.73%,P≤0.020%,S≤0.010%,Cr 8.40～9.60%,W 2.33～3.17%,Co 2.80～3.25%,Cu 0.40～1.20%,V 0.13～0.27%,Nb 0.03～0.10%,N 0.005～0.019%,B 0.008～0.022%,Ni≤0.13%,Ti≤0.02%,Al≤0.015%,O≤0.0040%,As≤0.015%,Sb≤0.015%,Bi≤0.005%,Sn≤0.020%,Pb≤0.015%,As+Sb+Bi+Sn+Pb≤0.035%, and the balance of Fe and unavoidable impurities.

Description

G115 large-specification continuous casting round billet forging method Technical Field The invention relates to the technical field of heat-resistant steel, in particular to a G115 large-specification continuous casting round billet forging method. Background Along with the rapid development of economy, the demand for energy is higher and higher, the thermal power generation is an important component of energy in China, but a series of environmental pollution problems caused by the thermal power generation are more and more serious in conflict with ecological civilization construction and environmental protection concepts in China, so the demand for high-efficiency and low-emission high-parameter thermal power generating units is more and more urgent. The higher the steam temperature and pressure parameters of the coal-fired power generation, the lower the energy consumption of the coal-fired power generation, the lower the pollutant emission, but the higher the performance requirements on the materials. P92 used by the ultra-supercritical unit with the high temperature resistance of 600 ℃ can not meet the requirement of a unit with higher parameters, and the requirement of the ultra-supercritical unit with the high temperature resistance of 630 ℃ to the material must reach 650 ℃. G115 is martensitic heat-resistant steel, as disclosed in China patent CN103045962B, the heat-resistant steel adopts a composite strengthening principle, contains W, co, cu, B, N and other strengthening elements, has high-temperature long-term structure stability, high-temperature durable strength and oxidation resistance which are all greatly higher than those of P92, is suitable for long-term use under the high-pressure working condition with the temperature below 650 ℃, and is superior to those of P92 under the temperature of 600 ℃ in the G115 through comparative study. The traditional manufacturing process of the G115 martensitic heat-resistant steel adopts die casting+ (electroslag) +forging+pipe manufacturing. However, the existing die casting+ (electroslag) +forging process has the disadvantages of high cost, long production period, complex process and improvement on organization and performance. In the prior art, chinese patent CN103045962B is an invention patent of G115, mainly related to aspects of component design, reinforcement concept, manufacturing method, performance characteristics, etc. of G115, but not related to a G115 forging method. Chinese patent CN108998650a relates to a method for manufacturing a seamless steel pipe with large diameter and thick wall for G115 in 630 ℃ ultra supercritical unit, which only relates to a process for manufacturing a seamless steel pipe with large diameter and thick wall for G115, and has no forging process. Chinese patent CN108950148a relates to a method for improving radial organization and performance uniformity of G115 heavy caliber thick wall pipe, and the technique also does not relate to a forging method of G115. Chinese patent CN114635023A relates to a production method of martensitic heat-resistant steel blank, mainly comprises a forging process of G115 electroslag ingot, and has the high-temperature homogenization temperature of 1200-1250 ℃, heat preservation of more than or equal to 80 hours, long time, low efficiency, forging heating temperature of 1140-1180 ℃, upsetting and drawing cannot be completed in one fire in the production process, therefore, 6 fires are required for three upsets and three drawing, the production period is long, the efficiency is low, and the patent does not relate to forging of G115 continuous casting blanks. Therefore, development of a novel efficient forging process suitable for G115 steel continuous casting large round billets is needed, the production efficiency is improved while the performance and quality are improved, and the cost is reduced. Disclosure of Invention The invention aims to provide a forging method of a G115 large-size continuous casting round billet, which can greatly shorten the forging production period of a G115 forging, improve the production efficiency by 30 percent, reduce the cost by 45 percent, and improve the structure and performance at the same time, wherein the performance of the produced G115 forging meets the requirements of a part 3, namely the forging, a novel martensitic heat-resistant steel 08Cr9W3Co3VNbCuBN (G115) tube blank and profile for a CSTM 00017.3-2021 power station, and other standard requirements, and the performance of a steel tube produced by using the forging as a blank meets the requirements of a seamless steel tube of a novel martensitic heat-resistant steel 08Cr9W3Co3VNbCuBN (G115) for a Q/OAPD 2253-2022 power station and a seamless steel tube of a novel martensitic heat-resistant steel 08Cr9W3Co3VNbCuBN (G115) for a CSTM 00017-2021 power station. In order to achieve the above purpose, the technical scheme of the invention is as follows: the invention adopts the continuous casting lar