阅读说明：本技术 一种含氮含铌高温合金中频炉冶炼工艺 (Intermediate frequency furnace smelting process for nitrogen-containing and niobium-containing high-temperature alloy ) 是由 *** 张鹏 孙立国 于杰 李飞扬 赵长顺 郭京 李旻才 李如 陈庆新 于 2019-12-02 设计创作，主要内容包括：本发明公开一种含氮含铌高温合金中频炉冶炼工艺,通过合理的冶炼工艺控制,改变合金晶界状态,大幅度提高合金750℃拉伸塑性的效果。本发明技术方案工艺流程如下：配料→备料→装料→给电→熔化80％左右→加氮化铬铁、金属锰→全熔→脱氧精炼→调成分→加铌铁、钒铁→微合金化→浇注；采用的GH1016合金中频炉冶炼的具体工艺措施中,明确了加铌-铁、钒-铁到出钢的时间控制在40min之内,是硬性要求；通过控制氮元素和铌、钒元素的接触时间,减少了冶炼过程中一次碳氮化物形成,从而使基体中保留了较高浓度的氮、铌元素,在锻后的晶界上析出项链状Z相,使合金750℃高温塑性得到大幅度提高。(The invention discloses a process for smelting a nitrogen-containing and niobium-containing high-temperature alloy in an intermediate frequency furnace, which changes the crystal boundary state of the alloy through reasonable smelting process control and greatly improves the effect of the 750 ℃ tensile plasticity of the alloy. The technical scheme of the invention comprises the following process flows: batching → stock preparation → charging → electrification → melting about 80% → adding ferrochromium nitride, manganese metal → full melting → deoxidation and refining → mixing component → adding ferroniobium and ferrovanadium → microalloying → pouring; in the specific technical measures of GH1016 alloy intermediate frequency furnace smelting, the time from niobium-iron and vanadium-iron addition to tapping is definitely controlled within 40min, which is a hard requirement; by controlling the contact time of the nitrogen element and the niobium and vanadium elements, the formation of primary carbonitride in the smelting process is reduced, so that the nitrogen and niobium elements with higher concentration are retained in the matrix, a necklace-shaped Z phase is precipitated on the forged crystal boundary, and the high-temperature plasticity of the alloy at 750 ℃ is greatly improved.)

1. a process for smelting a nitrogen-containing and niobium-containing high-temperature alloy in an intermediate frequency furnace is characterized by comprising the following steps of: the process flow is as follows: batching → stock preparation → charging → electrification → melting about 80% → adding ferrochromium nitride, manganese metal → full melting → deoxidation and refining → mixing component → adding ferroniobium and ferrovanadium → microalloying → pouring;

① chemical components of the nitrogen-containing niobium-containing high-temperature alloy GH1016 alloy comprise (by weight percent) not more than 0.08 of carbon, 19.0 to 22.0 of chromium, 5.0 to 6.0 of tungsten, 2.6 to 3.3 of molybdenum, 0.9 to 1.4 of niobium, 0.13 to 0.25 of nitrogen, 32.0 to 36.0 of nickel, the balance of iron, 0.1 to 0.3 of vanadium, not more than 1.80 of manganese, not more than 0.60 of silicon, not more than 0.015 of sulfur, not more than 0.020 of phosphorus, not more than 0.01 of boron and not more than 0.05 of cerium;

② calculating the amount of each raw material required by smelting according to the chemical composition of the alloy;

③ the raw materials include H1-nickel plate, M-chromium, ferromolybdenum, ferrotungsten, ferrovanadium, ferrosilicon, ferroniobium, M-manganese, ferrochromium nitride, and 100% carbon electrode, and the raw materials have clean and dry surface, no oil stain and oxidation, and accurate chemical components;

④ the charging sequence is that nickel plate, ferromolybdenum, ferrotungsten, refined steel and M-chromium are added in sequence, ferrochromium nitride and manganese metal are added when about 80% is melted;

⑤ deoxidizing and refining in a diffusion deoxidizing mode after full melting for 30-60 min;

⑥ analyzing the components in the furnace, and adjusting elements such as chromium, nitrogen, tungsten, molybdenum and the like according to the result;

⑦ adding ferroniobium and ferrovanadium in calculated amount, and keeping for 5-15 min;

⑧ adding boron, cerium, etc. to carry out micro-alloying;

⑨ tapping and pouring.

2. The intermediate frequency furnace smelting process of the nitrogen-containing and niobium-containing high-temperature alloy according to claim 1, characterized by comprising the following steps of: the time from the addition of ferrocolumbium and ferrovanadium to tapping and pouring is controlled within 40 min.

3. The intermediate frequency furnace smelting process of the nitrogen-containing and niobium-containing superalloy as claimed in claim 1 or 2, wherein: adding ferrocolumbium and ferrovanadium for 5 min; the pouring time from the addition of ferrocolumbium and ferrovanadium to tapping is 28 min.

4. The intermediate frequency furnace smelting process of the nitrogen-containing and niobium-containing superalloy as claimed in claim 1 or 2, wherein: adding ferrocolumbium and ferrovanadium for 10 min; the casting time from the adding of the ferrocolumbium and the ferrovanadium to tapping is 20 min.

5. The intermediate frequency furnace smelting process of the nitrogen-containing and niobium-containing superalloy as claimed in claim 1 or 2, wherein: adding ferrocolumbium and ferrovanadium for 15 min; the pouring time from the addition of ferrocolumbium and ferrovanadium to tapping is 40 min.

Technical Field

The invention belongs to a special alloy smelting process, and particularly relates to an intermediate frequency furnace smelting process suitable for nitrogen-containing and niobium-containing GH1016 alloy.

Background

The GH1016 alloy is an iron-nickel-chromium-based high-temperature alloy strengthened by niobium, nitrogen, tungsten, molybdenum and vanadium, has the main characteristic of being strengthened by nitrogen, and is a typical case of a low-cost high-temperature alloy which is self-developed in China and replaces nickel by nitrogen. The alloy has high-temperature heat resistance and thermal stability, can be used below 950 ℃ for a long time, and is strengthened by a Z phase (chromium niobium nitride with tetragonal lattice) (see figure 1). The problem of medium temperature low plasticity exists for a long time, particularly in GH1016 alloy products produced by an intermediate frequency furnace, the plasticity at 750 ℃ always wanders around a standard line (the elongation is more than or equal to 30 percent, and the surface shrinkage is more than or equal to 35 percent).

Disclosure of Invention

The invention discloses a process for smelting a nitrogen-containing and niobium-containing high-temperature alloy in an intermediate frequency furnace, which changes the crystal boundary state of the alloy through reasonable smelting process control and greatly improves the effect of the 750 ℃ tensile plasticity of the alloy.

1. The technical scheme of the invention comprises the following process flows:

batching → stock preparation → charging → electrification → melting about 80% → adding ferrochromium nitride, manganese metal → full melting → deoxidation and refining → mixing component → adding ferroniobium, ferrovanadium → micro-alloying → pouring

2. Specific process measures

① GH1016 alloy has chemical compositions in percentage by weight in accordance with the specification of Table 1, and is prepared according to the chemical compositions.

TABLE 1 GH1016 alloy chemistry

TABLE 1 (continuation)

Element(s)

V

Mn

Si

S

P

B

Ce

Technical standard

0.1～0.3

≤1.80

≤0.60

≤0.015

≤0.020

≤0.01

≤0.05

② the amount of each raw material required for smelting is calculated according to the alloy composition control requirement.

③ the raw material adopts H1-nickel plate, M-chromium, ferromolybdenum, ferrotungsten, ferrovanadium, ferrosilicon, ferroniobium, M-manganese, ferrochromium nitride, 100% carbon electrode, the surface of the raw material must be clean and dry, no oil stain and oxidation, accurate chemical composition;

④ the charging sequence is that nickel plate, ferromolybdenum, ferrotungsten, refined steel and M-Cr are added in sequence, and ferrochromium nitride and manganese metal are added when about 80% is melted.

⑤ deoxidizing and refining by diffusion deoxidizing method after melting for 30-60 min.

⑥, and adjusting the element components such as chromium, nitrogen, tungsten, molybdenum and the like according to the result.

⑦ adding ferroniobium and ferrovanadium in calculated amount, and keeping for 5-15 min.

⑧ and adding boron, cerium, etc. to make micro-alloying.

⑨ tapping and pouring.

⑩ the time from step ⑦ to tapping pouring is controlled within 40 min.

Description of the invention points:

① specifies the time from the addition of ferrocolumbium and ferrovanadium to tapping, which is a hard requirement.

② GH1016 alloy intermediate frequency furnace smelting detailed process, no relevant literature document is recorded.

③ the contact time of nitrogen element and niobium and vanadium element is controlled to reduce the formation of primary carbonitride in the smelting process, thus keeping the nitrogen and niobium elements with higher concentration in the matrix, and precipitating necklace-shaped Z phase (see figure 2) on the forged crystal boundary, thus greatly improving the 750 ℃ high temperature plasticity of the alloy.

Drawings

FIG. 1 shows that the precipitated phase on the grain boundary of the bar is very little (100X) before the process is improved;

FIG. 2 shows that after the process is improved, a great amount of necklace-shaped precipitated phases (100X) are precipitated on the grain boundaries of the bars.

Detailed Description

The present invention is described in detail below by way of examples.