CN103774061B

CN103774061B - Leaf joint forging and manufacture craft thereof

Info

Publication number: CN103774061B
Application number: CN201410006258.2A
Authority: CN
Inventors: 刘智
Original assignee: WUXI PAIKE HEAVY CASTING AND FORGING CO Ltd
Current assignee: Wuxi Parker new materials Polytron Technologies Inc
Priority date: 2014-01-07
Filing date: 2014-01-07
Publication date: 2015-11-18
Anticipated expiration: 2034-01-07
Also published as: CN103774061A

Abstract

The present invention relates to a kind of leaf joint forging and manufacture craft thereof, comprise the steps: the first step: get the raw materials ready; Second step: cogging is forged, comprises heating, forging, annealing; 3rd step: blanking, excision steel ingot is end to end; 4th step: shaping forging, comprises heating, base, rolls ring, annealing; 5th step: thermal treatment, comprises normalizing, first time tempering, quenching, second time tempering, third time tempering; 6th step: UT (Ultrasonic Testing); 7th step: Physico-chemical tests; 8th step: precision work; 9th step: finished product packing: make leaf joint forging obtain good Refined microstructure and high temperature endurance performance, also there is good tensile strength and yield strength simultaneously.

Description

Leaf joint forging and manufacture craft thereof

Technical field

The present invention relates to forging process Technology field, especially a kind of material is the stainless leaf joint forging of high temperature iron ferritic and manufacture craft thereof.

Background technology

At present, the temperature parameter of built supercritical generating sets is mostly at about 550 DEG C, the working temperature of supercritical unit of new generation just is in the design then 620 DEG C, the high-temperature behavior of higher temperature parameter to unit material is had higher requirement, and leaf joint is as the core component of Steam Turbine, can its high-temperature behavior meet the success or failure that service requirements is then related to steam turbine of new generation.High temperature ferritic stainless steel has good high-temperature corrosion resistance performance and high temperature endurance performance, but general crystal grain is thicker, tensile strength and yield strength on the low side, be difficult to meet service requirements.

Summary of the invention

The applicant, for the shortcoming in above-mentioned existing production technology, provides a kind of leaf joint forging and manufacture craft thereof, thus makes leaf joint forging obtain good Refined microstructure and high temperature endurance performance, also has good tensile strength and yield strength simultaneously.

The technical solution adopted in the present invention is as follows:

A kind of leaf joint forging, described in the material composition of leaf joint forging is composed as follows:

C：0.14～0.15%，

Si：≤0.1%，

Mn：0.4～0.45%，

P：≤0.005%，

S：≤0.005%，

Cr：9.20～9.50%，

Mo：1.50～1.60%，

Ni：0.15～0.20%，

Co：1.25～1.30%，

Ti：≤0.005%，

V：0.20～0.25%，

Al：≤0.010%，

N：0.020～0.030%，

Nb：0.05～0.06%，

B：90～110ppm，

Cu：≤0.10%，

As：≤0.020%，

Sb：≤0.0015%，

Sn：≤0.015%；

All the other are Fe element;

And to gas content analysis: hydrogen≤1.5ppm, oxygen≤35ppm.

Produce a manufacture craft for above-mentioned leaf joint forging products, comprise the steps:

The first step: get the raw materials ready;

Second step: cogging is forged, comprises heating, forging, annealing;

3rd step: blanking, excision steel ingot is end to end;

4th step: shaping forging, comprises heating, base, rolls ring, annealing;

5th step: thermal treatment, comprises normalizing, first time tempering, quenching, second time tempering, third time tempering;

6th step: UT (Ultrasonic Testing);

7th step: Physico-chemical tests;

8th step: precision work;

9th step: finished product packing.

Further improvement as technique scheme:

Wherein in second step, Heating temperature is 1220 DEG C-1240 DEG C, and heat-up time is 3-5 hour.

Wherein in the 4th step, Heating temperature is 1150 DEG C-1180 DEG C, and soaking time is 3-4 hour.

Wherein in the 5th step, normalizing Heating temperature is 1110 DEG C, insulation 5-6 hour after temperature, and quenching temperature is 1100 DEG C, insulation 3-4 hour, air-cooled after coming out of the stove.

Wherein in the 5th step, the type of cooling of normalizing adopts air cooling, and the type of cooling of first time tempering adopts the cold rear air cooling of stove, and the modified type of cooling of quenching adopts air-cooled, the modified type of cooling of second time tempering adopts air cooling, and the modified type of cooling of third time tempering adopts the cold rear air cooling of stove.

Beneficial effect of the present invention is as follows:

Heat operation in cogging forging process of the present invention, can improve the moulding of steel ingot, can accomplish that gross distortion is with the casting flaw of pressing steel ingot when being beneficial to forging.

Cogging of the present invention forging is carried out when steel ingot does not excise rising head, can make the forging conjunction before not oxidized of the defect such as loose in steel ingot.

Of the present inventionly roll ring operation, adopt lower start rolling temperature, improve finishing temperature simultaneously, then carry out annealing and Slow cooling, can the microstructure of refinement forging.

Modified type of cooling employing of the present invention is air-cooled, air cooling, stove are cold combines, and not only can improve the toughness of forging and obtain good comprehensive mechanical property, and organizing more even.

The present invention, in production technique, makes full use of heating, cogging is forged, anneals, rolls the operation such as ring, thermal treatment and combine, obtain tiny microstructure, have good high temperature endurance performance and ambient temperature mechanical properties simultaneously.Salient features of the present invention is: grain fineness number >=3 grade, high-temperature and durable time >=500h(620 DEG C, 220MPa), yield strength 680 ~ 780, tensile strength≤950, unit elongation >=13, relative reduction in area >=40, average impact merit >=24J.

Embodiment

The following describes the specific embodiment of the present invention.

The leaf joint forging of the present embodiment, the material composition of leaf joint forging is composed as follows:

C：0.14～0.15%，

Si：≤0.1%，

Mn：0.4～0.45%，

P：≤0.005%，

S：≤0.005%，

Cr：9.20～9.50%，

Mo：1.50～1.60%，

Ni：0.15～0.20%，

Co：1.25～1.30%，

Ti：≤0.005%，

V：0.20～0.25%，

Al：≤0.010%，

N：0.020～0.030%，

Nb：0.05～0.06%，

B：90～110ppm，

Cu：≤0.10%，

As：≤0.020%，

Sb：≤0.0015%，

Sn：≤0.015%；

All the other are Fe element;

And to gas content analysis: hydrogen≤1.5ppm, oxygen≤35ppm.

The material composition of leaf joint forging is composed as follows:

C：0.15%，

Si：0.0084%，

Mn：0.42%，

P：0.004%，

S：0.002%，

Cr：9.35%，

Mo：1.575%，

Ni：0.19%，

Co：1.25%，

Ti：0.001%，

V：0.21%，

Al：0.009%，

N：0.02%，

Nb：0.059%，

B：100ppm，

Cu：0.064%，

As：0.013%，

Sb：0.001%

Sn：0.005%，

All the other are Fe element;

And to gas content analysis: hydrogen 1.0ppm, oxygen 30ppm.

The manufacture craft of the leaf joint forging of the use claim 1 of the present embodiment, comprises the steps:

The first step: get the raw materials ready;

Second step: cogging is forged, comprises heating, forging, annealing;

3rd step: blanking, excision steel ingot is end to end;

4th step: shaping forging, comprises heating, base, rolls ring, annealing;

6th step: UT (Ultrasonic Testing);

7th step: Physico-chemical tests;

8th step: precision work;

9th step: finished product packing.

Embodiment one:

The first step: get the raw materials ready;

Second step: cogging is forged, comprise heating, forging, anneal, Heating temperature is 1230 DEG C, and during forging, employing Upsetting slightly pulls out the forging mode combined, and total forging ratio is 8, carries out the annealing of 720 DEG C × 8h and stove is chilled to room temperature after forging;

3rd step: blanking, excision steel ingot is end to end;

4th step: shaping forging, comprises heating, base, rolls ring, annealing; Heating temperature is 1180 DEG C, and final forging temperature is 950 DEG C, carries out the annealing of 720 DEG C × 8h and stove is chilled to room temperature after rolling;

In normalizing process, normalizing temperature is 1110 DEG C, and be incubated 5 hours, the type of cooling is air cooling, and tempering temperature is 660 DEG C for the first time, and soaking time is 8 hours, is chilled to 200 DEG C of air coolings of coming out of the stove after insulation with the speed stove of 20 DEG C/h;

In quenching process, quenching temperature is 1100 DEG C, be incubated 4 hours, the type of cooling is air-cooled, and second time tempering temperature is 570 DEG C, soaking time is 8 hours, air cooling come out of the stove after insulation to room temperature, and tempering temperature is 700 DEG C for the third time, and soaking time is 8 hours, speed stove with 20 DEG C/h after insulation is chilled to 450 DEG C, then air cooling of coming out of the stove after being chilled to 200 DEG C with the speed stove of 30 DEG C/h.

6th step: UT (Ultrasonic Testing);

7th step: Physico-chemical tests; Physico-chemical tests result is: grain fineness number 3 grades, high-temperature and durable time > 500h(620 DEG C, 220MPa), yield strength 725MPa, tensile strength 855MPa, unit elongation 19%, relative reduction in area 63%, average impact merit 54J;

8th step: precision work;

9th step: finished product packing.

More than describing is explanation of the invention, and be not the restriction to invention, limited range of the present invention, see claim, within protection scope of the present invention, can do any type of amendment.

Claims

1. a manufacture craft for leaf joint forging, is characterized in that: described in the material composition of leaf joint forging is composed as follows:

C:0.14～0.15%,

Si:≤0.1%,

Mn:0.4～0.45%,

P:≤0.005%，

S:≤0.005%,

Cr:9.20～9.50%,

Mo:1.50～1.60%，

Ni:0.15～0.20%,

Co:1.25～1.30%,

Ti:≤0.005%，

V:0.20～0.25%，

Al:≤0.010%,

N:0.020～0.030%,

Nb:0.05～0.06%,

B:90～110ppm,

Cu:≤0.10%,

As:≤0.020%,

Sb:≤0.0015%,

Sn:≤0.015%；

All the other are Fe element;

And to gas content analysis: hydrogen≤1.5ppm, oxygen≤35ppm;

The manufacture craft of leaf joint forging, comprises the steps:

The first step: get the raw materials ready;

Second step: cogging is forged, comprises heating, forging, annealing;

3rd step: blanking, excision steel ingot is end to end;

4th step: shaping forging, comprises heating, base, rolls ring, annealing;

6th step: UT (Ultrasonic Testing);

7th step: Physico-chemical tests;

8th step: precision work;

9th step: finished product packing.

2. the manufacture craft of leaf joint forging as claimed in claim 1, it is characterized in that: wherein in second step, Heating temperature is 1220 DEG C-1240 DEG C, and heat-up time is 3-5 hour.

3. the manufacture craft of leaf joint forging as claimed in claim 1, is characterized in that: wherein in the 4th step, Heating temperature is 1150 DEG C-1180 DEG C, and soaking time is 3-4 hour.

4. the manufacture craft of leaf joint forging as claimed in claim 1, is characterized in that: wherein in the 5th step, normalizing Heating temperature is 1110 DEG C, insulation 5-6 hour after temperature, and quenching temperature is 1100 DEG C, insulation 3-4 hour, air-cooled after coming out of the stove.

5. the manufacture craft of leaf joint forging as claimed in claim 1, it is characterized in that: wherein in the 5th step, the type of cooling of normalizing adopts air cooling, the type of cooling of first time tempering adopts the cold rear air cooling of stove, the modified type of cooling of quenching adopts air-cooled, the modified type of cooling of second time tempering adopts air cooling, and the modified type of cooling of third time tempering adopts the cold rear air cooling of stove.