CN105170869A

CN105170869A - Forging method capable of improving transverse mechanical property of 17-4PH forge pieces

Info

Publication number: CN105170869A
Application number: CN201510602247.5A
Authority: CN
Inventors: 李占华; 高全德; 艾俊林; 孙振环; 张凯亮; 双伟鹏; 陈俸军; 王立新
Original assignee: Zhongyuan Special Steel Co Ltd
Current assignee: Zhongyuan Special Steel Co Ltd
Priority date: 2015-09-21
Filing date: 2015-09-21
Publication date: 2015-12-23

Abstract

The invention relates to a forging method capable of improving the transverse mechanical property of 17-4PH forge pieces. The method includes the steps that the defective portions of the two ends of an electroslag ingot are sawn off before the electroslag ingot is heated, i.e., the heating temperature is 1160 DEG C, the initial forging temperature is 1000-1100 DEG C, the final forging temperature is 900 DEG C, and the temperature rising rate and the heat preservation period are strictly controlled; a 5000T oil press performs axial primary upsetting and drawing and radial secondary upsetting and drawing; in the forging process, the preheating temperature is 400-450 DEG C, preheating lasts for 5 hours, temperature of the first stage is kept at 850 DEG C for 5 hours, temperature of the second stage is kept at 1100 DEG C for 6 hours, and temperature of the final stage is kept at 1160 DEG C for 5 hours; and the temperature rising rate of the first stage is smaller than 60 DEG C per hour, the temperature rising rate of the second stage is smaller than 100 DEG C per hour, and the temperature rising rate of the third stage depends on power. The forging method capable of improving the transverse mechanical property of 17-4PH forges increases the density of forges and greatly improves the transverse mechanical property of forges, and the use requirements for forges in a severe environment are met.

Description

A kind of forging method improving 17-4PH forging horizontal mechanical performance

Technical field

The invention belongs to technical field of forging, be specifically related to a kind of forging method improving 17-4PH forging horizontal mechanical performance.

Background technology

Pressure vessel inner core is the core component of pressure vessel systems, work under air pressure 500MPa environment, petroleum equipment clack box requires cold insulation, their serviceability requires very high, all requires higher horizontal mechanical performance, and traditional forging method is mainly along the longitudinal upsetting pull of forging, general employing 3 upsetting 3 is pulled out, although this method can improve the horizontal mechanical performance of forging, DeGrain, be difficult to meet the instructions for use of client to forging.Therefore means of effectively forging must be taked to improve the horizontal mechanical performance of forging.For the deficiency of traditional forging method, to improve for the purpose of forging horizontal mechanical performance, spy has invented this forging method, the means that this method is mainly taked are directly along forging radial direction (namely laterally) upsetting pull, make the significantly homogeneous deformation of the horizontal interior tissue of forging, thus improve horizontal mechanical performance.

Summary of the invention

The object of the invention is to overcome above-mentioned deficiency of the prior art and a kind of forging method meeting the raising 17-4PH forging horizontal mechanical performance that properties of product require is provided.

Technical scheme of the present invention is achieved in that a kind of forging method improving 17-4PH forging horizontal mechanical performance, and this forging method is as follows: before ESR ingot heating, first sawing ESR ingot two ends defect; Heating-up temperature 1160 DEG C, initial forging temperature 1100-1000 DEG C and final forging temperature 900 DEG C, strict control heating rate and temperature retention time; 5000T hydraulic press carries out axis 1 jumping-up, pulling and radial 2 jumping-ups, pulling; In forging process: preheat temperature 400 ~ 450 DEG C, 5 hours preheating time, first stage holding temperature 850 DEG C, temperature retention time 5 hours, second stage holding temperature 1100 DEG C, temperature retention time 6 hours, last holding stage 1160 DEG C, temperature retention time 5 hours; First stage heating rate < 60 DEG C/h, second stage heating rate < 100 DEG C/h, power is pressed in phase III intensification.

The heavy 7100Kg of ESR ingot, utilization rate 71%, ESR ingot sawing two ends, axial jumping-up, to H=850, flat anvil pulls out to hot 750mm × 800mm, radial micro-chamfered edge, drafts 80mm about 700.

The heavy 7600Kg of ESR ingot, utilization rate 71%, ESR ingot sawing two ends, axial jumping-up, to H=800, flat anvil pulls out to hot 730mm × 730mm, radial micro-chamfered edge, drafts 80mm about 700.

Adopt axially 1 time, longitudinal twice, the performance data of forging: R _{p
(0.2
)}=1100MPa, Rm=1150MPa, A=7%, Z=32%; R _{p
(0.2
)}=1050MPa, Rm=1100MPa, A=13.5%, Z=43%.

The good effect that technical scheme of the present invention produces is as follows: before ESR ingot heating, first sawing ESR ingot two ends defect, for follow-up three-dimensional jumping-up pulling provides favourable conditions; Common forging method is only in axial jumping-up, pulling, the present invention breaches Traditional Thinking, if space three-dimensional direction is X, Y, Z, not only in axial Z jumping-up, pulling, simultaneously in radial X, Y jumping-up, pulling, this invention has fully carried out three-dimensional upsetting pull to raw material ESR ingot, completely eliminate the defect of ESR ingot itself, improve the density of forging, significantly improve the horizontal mechanical performance of forging simultaneously, meet product instructions for use in the presence of a harsh environment.

Accompanying drawing explanation

Fig. 1 is ESR ingot structural representation before forging process for fuel of the present invention.

Fig. 2 is the structural representation of forging after axial Z-direction jumping-up.

Fig. 3 be forging radially X-direction pulling after structural representation.

Fig. 4 is the structural representation of forging radially after X-direction jumping-up.

Fig. 5 be forging radially Y-direction pulling after structural representation.

Fig. 6 is the structural representation of forging radially after Y-direction jumping-up.

Fig. 7 is the structural representation after forging longitudinally Z-direction pulling.

Detailed description of the invention

Embodiment one

Improve a forging method for 17-4PH forging horizontal mechanical performance, as shown in Fig. 1,2,3,4,5,6,7, product requirement is as follows: pressure vessel inner core, grade of steel 05Cr17Ni4Cu4Nb, ESR ingot weight 7100Kg, utilization rate 71%, the sawing of ESR ingot two ends, weight 6650Kg after sawing.Furnace temperature 1160 DEG C, initial forging temperature 1100-1000 DEG C, final forging temperature 900 DEG C, total forging ratio 7.66.Forging method is as follows:

Step 01: before ESR ingot heating, first sawing ESR ingot two ends defect, then heats in heating furnace;

Step 02: 5000T hydraulic press press Fig. 1 vertically jumping-up to H=850(~ φ 1130), by Fig. 2, about 700, on flat anvil, pulling is to hot 750mm × 800mm(drafts≤150, and feed >=500, note taking anvil, wrong anvil), radial micro-chamfered edge, drafts 80mm;

Step 03: heat in heating furnace, is incubated 3.5 hours;

Step 04: 5000T hydraulic press press Fig. 3 radially jumping-up to H=700, by Fig. 4 about 700 on flat anvil pulling pull out direction become 90 angles to Fig. 2 radial direction, more radially pulling to hot 800 × 750, micro-chamfered edge, drafts 80mm;

Step 05: in heating furnace heating, be then incubated 3.5 hours;

Step 06: 5000T hydraulic press press Fig. 5 radially jumping-up to H=700, about 700 on flat anvil pulling vertically to hot mouth 500, all directions 520 on flat anvil 700 about;

Step 07: finish forge is to finished product in 1400T precise forging machine.

Pressure vessel inner core requires that horizontal mechanical property is Rp (0.2) >=1140MPa, Rm >=1190MPa, A >=10%, Z >=40%; Through the inner core of the method forging, final horizontal mechanical performance result is: Rp (0.2) >=1203MPa, Rm >=1260MPa, A >=12%, Z >=54%.

From the above, indices is all qualified.

Embodiment two

Improve a forging method for 17-4PH forging horizontal mechanical performance, as shown in Fig. 1,2,3,4,5,6,7, product requirement is as follows: petroleum equipment clack box, grade of steel 05Cr17Ni4Cu4Nb, ESR ingot weight 7600Kg, utilization rate 71%, the sawing of ESR ingot two ends, weight 7150Kg after sawing.Furnace temperature 1160 DEG C, initial forging temperature 1100-1000 DEG C, final forging temperature 900 DEG C, total forging ratio 8.24.Forging method is as follows:

Step 02: 5000T hydraulic press press Fig. 1 vertically jumping-up to H=800(~ φ 1200), by Fig. 2, about 700, on flat anvil, pulling is to hot 730mm × 730mm(drafts≤150, and feed >=500, note taking anvil, wrong anvil), radial micro-chamfered edge, drafts 80mm;

Step 03: heat in heating furnace, is incubated 3.5 hours;

Step 04: 5000T hydraulic press press Fig. 3 radially jumping-up to H=800, by Fig. 4 about 700 on flat anvil pulling pull out direction become 90 angles to Fig. 2 radial direction, more radially pulling to hot 730 × 730, micro-chamfered edge, drafts 80mm;

Step 05: in heating furnace heating, be then incubated 3.5 hours;

Step 06: 5000T hydraulic press press Fig. 5 radially jumping-up to H=900, about 700, flat anvil pulls out finished product vertically, chop to fall pincers handle;

Step 07: finish forge is to finished product in 1400T precise forging machine.

Petroleum equipment clack box requires horizontal mechanical performance: Rp (0.2) >=980MPa, Rm >=1060MPa, A >=16%, Z >=55%; Through the clack box of the method forging, final mechanical property is: Rp (0.2) >=1136MPa, Rm >=1194MPa, A >=17%, Z >=59%

From the above, indices is all qualified.

Through many experiments, the method is promoted in my company's forging field, and be not only applied in 17-4PH material, be applied to equally in other material requiring higher transverse mechanical combination property, the invention of this forging method, for my company creates considerable economic benefit.

Claims

1. improve a forging method for 17-4PH forging horizontal mechanical performance, it is characterized in that: this forging method is as follows: before ESR ingot heating, first sawing ESR ingot two ends defect; Heating-up temperature 1160 DEG C, initial forging temperature 1100-1000 DEG C and final forging temperature 900 DEG C, strict control heating rate and temperature retention time; 5000T hydraulic press carries out axis 1 jumping-up, pulling and radial 2 jumping-ups, pulling; In forging process: preheat temperature 400 ~ 450 DEG C, 5 hours preheating time, first stage holding temperature 850 DEG C, temperature retention time 5 hours, second stage holding temperature 1100 DEG C, temperature retention time 6 hours, last holding stage 1160 DEG C, temperature retention time 5 hours; First stage heating rate < 60 DEG C/h, second stage heating rate < 100 DEG C/h, power is pressed in phase III intensification.

2. a kind of forging method improving 17-4PH forging horizontal mechanical performance according to claim 1, it is characterized in that: the heavy 7100Kg of ESR ingot, utilization rate 71%, ESR ingot sawing two ends, axial jumping-up is to H=850, pulling extremely hot 750mm × 800mm on flat anvil about 700, radial micro-chamfered edge, drafts 80mm.

3. a kind of forging method improving 17-4PH forging horizontal mechanical performance according to claim 1, it is characterized in that: the heavy 7600Kg of ESR ingot, utilization rate 71%, ESR ingot sawing two ends, axial jumping-up is to H=800, pulling extremely hot 730mm × 730mm on flat anvil about 700, radial micro-chamfered edge, drafts 80mm.

4. a kind of forging method improving 17-4PH forging horizontal mechanical performance according to claim 1, is characterized in that: adopt axially 1 upsetting pull, radial 2 upsetting pulls, the performance data of forging:

R _{p
（0.2
）}=1203MPa，Rm=1260MPa，A=12%，Z=54%；R _{p
（0.2
）}=1136MPa，Rm=1194MPa，A=17%，Z=59%。