一种镍基高温合金锻件和棒材获得均匀超细晶粒的方法A method for obtaining uniform ultrafine grains of nickel-based superalloy forgings and rods
本发明涉及一种镍基高温合金GH4169合金各类锻件，如盘、叶轮、环、轴和叶片；各类棒材，如锻棒、轧棒，获得ASTM10级以上均匀超细晶粒的方法。The invention relates to a method for obtaining uniform ultra-fine grains above ASTM 10 for various forgings of nickel-base superalloy GH4169 alloy, such as disks, impellers, rings, shafts and blades; and various rods, such as forged rods and rolled rods.
众所周知，GH4169合金广泛用于航空、航天、核电站及石化工业中的关键零部件制造，比如燃气轮发动机上的涡轮盘、压气机盘、环形件、涡轮轴及压气机叶片等等。而为了改善燃气轮机上述重要零件的高、低周疲劳性能，则要求该合金的晶粒度均匀细化达到ASTM10级以上。美国专利US3660177提出了一种采用热机械加工生产出具有均匀细小晶粒的1N718合金锻件及棒材的方法。但是，该方法披露的技术细节不足，尤其是锻造温度较低，析出的金相组织是短粗针状魏氏体δ相，因而对终锻要求比较苛刻。采用一般的细晶工艺，该合金在一般的锻压设备上难以达到ASTM10级以上的均匀超细晶粒。As we all know, GH4169 alloy is widely used in the manufacture of key components in aviation, aerospace, nuclear power plants and petrochemical industries, such as turbine disks, compressor disks, rings, turbine shafts and compressor blades on gas turbine engines. In order to improve the high and low cycle fatigue performance of the above-mentioned important parts of the gas turbine, it is required that the grain size of the alloy be uniformly refined to reach ASTM 10 or above. US Patent US3660177 proposes a method for producing 1N718 alloy forgings and rods with uniform fine grains by thermomechanical processing. However, the technical details disclosed by this method are insufficient, especially the forging temperature is low, and the precipitated metallographic structure is short and thick acicular Widmansterite δ phase, so the requirements for final forging are relatively strict. Using the general fine-grain process, it is difficult for the alloy to achieve uniform ultra-fine grains above ASTM 10 on general forging equipment.
本发明的目的在于提供一种在普通的锻压设备，比如锤、压力机、液压机和普通轧钢机、环轧机上，就能使GH4169高温合金锻件或棒材得到ASTM10级以上均匀超细晶粒的易于操作的方法。The purpose of the present invention is to provide a kind of common forging equipment, such as hammer, press, hydraulic press and ordinary rolling mill, ring rolling mill, just can make GH4169 superalloy forgings or rods obtain ASTM10 level or above uniform ultra-fine grain Easy to operate method.
本发明的技术解决方案为下料后将坯料析出δ相，通过对坯料的热机械加工、最终成形及热处理，使合金获得均匀超细晶粒。其特点是按下述步骤析出均匀的网兰状魏氏体δ相：a.在1010℃--1030℃进行大于25％的予变形，b.进行第一次网兰处理，工艺参数880--900℃保温8--10h空冷，c.包套及锻造或轧制后进行第二次网兰处理，工艺参数同第一次网兰处理。另外，在第一次网兰处理及包套后，坯料在1010℃-1030℃进行变形大于30％的锻造或轧制。其次，在第二次网兰处理后，坯料在普通的锻压设备上进行变形大于25％的终锻或终轧，工艺参数取980℃-1010℃及视坯料大小和具体要求采用空冷、油冷或水冷。最后，在720℃-620℃直接时效或者在970℃1h固溶，然后在720℃-620℃时效处理。这样，即可得到DA状态(前者)或优质高强状态(后者)ASTM10级以上均匀超细晶粒的锻件和棒材。当然当坯料晶粒大小比较均匀时，在析出δ相的步骤中可以不进行预变形，即下料后直接进行第一次网兰处理。当第一次网兰处理后坯料的晶粒大小比较均匀的组织时，在析出δ相的步骤中可以不进行第二次网兰处理即包套后直接进行终锻或终轧。另外，当最终成形采用等温成形设备时，坯料进行第一次网兰处理后不必包套即可进行终锻或终轧。The technical solution of the invention is to precipitate the δ phase from the billet after blanking, and obtain uniform ultrafine grains of the alloy through thermomechanical processing, final forming and heat treatment of the billet. It is characterized by the precipitation of uniform blue-like widmanstattenite δ phase according to the following steps: a. Pre-deformation of more than 25% at 1010°C--1030°C; b. First net blue treatment, process parameters 880- Insulate at -900°C for 8--10h and air-cool, c. After sheathing and forging or rolling, carry out the second netting treatment, and the process parameters are the same as the first netting treatment. In addition, after the first net blue treatment and sheathing, the billet is forged or rolled at 1010°C-1030°C with a deformation greater than 30%. Secondly, after the second net blue treatment, the billet is subjected to final forging or final rolling with a deformation greater than 25% on ordinary forging equipment. or water cooling. Finally, direct aging at 720°C-620°C or solid solution at 970°C for 1 hour, and then aging treatment at 720°C-620°C. In this way, forgings and rods with uniform ultrafine grains above ASTM grade 10 can be obtained in DA state (the former) or high-quality high-strength state (the latter). Of course, when the grain size of the billet is relatively uniform, pre-deformation may not be performed in the step of precipitating the δ phase, that is, the first netting treatment is directly carried out after blanking. When the grain size of the billet after the first net blue treatment is relatively uniform, the final forging or final rolling can be directly carried out after the second net blue treatment, that is, sheathing, in the step of precipitating the δ phase. In addition, when isothermal forming equipment is used for final forming, the blank can be final forged or final rolled without wrapping after the first net blue treatment.
下面结合附图看实施例。See embodiment below in conjunction with accompanying drawing.
附图1为本发明的工艺流程图。其中，由下料工序到锻造或轧制称为第一次预处理，至终锻或终轧前称为第二次预处理，二者加在一起可统称之为预处理，其目的是先得到比较均匀分布的网兰状魏氏体δ相组织结构，然后在低于δ相溶解温度下变形，将网兰状魏氏体δ相破碎，得到球状δ相组织，由球状δ相围成新的网兰，形成新的细晶粒周界，在随后的热处理过程中使细晶进一步完善、晶粒进一步均匀。附图2为一种实施例下料后的金相组织图。其化学成分见表一，其中，合金呈非时效状态，化学成分没有严格要求，无明显铌偏析，晶粒度为ASTM5-7级，是典型的晶粒分布不均匀例子呈项链状。将所下之料按图一流程加工，第一次网兰处理后得到比较均匀分布的网兰状魏氏体δ相(见附图3)，用硅酸铝纤维粘及1Cr18Ni9Ti板包套后锻造或轧制，得到球状δ相组织(见附图4)。最后，模具经预热便可直接在普通压力机上终锻。在热处理工序中，DA处理后得到了均匀超细晶粒组织(见附图5)和δ相组织结构(见附图6)；经固溶时效处理后得到了均匀超细晶粒组织(见附图7)和δ相组织结构(见附图8)。附图9为另一种实施例的情况，即下料后晶粒组织分布均匀的金相图。其化学成份见表2，其中合金状态，晶粒度等级等均与上例相同。此时，不进行预变形处理而直接进入网兰处理工序即可得到如附图3所示均匀分布的网兰状魏氏体δ相。按图1流程继续加工，最终仍能得到如附图5及附图7那样的均匀超细晶粒。Accompanying drawing 1 is process flow chart of the present invention. Among them, the first pretreatment from the blanking process to forging or rolling is called the first pretreatment, and the second pretreatment to the final forging or final rolling is called the second pretreatment. Obtain a more evenly distributed reticulated Widmanstattenite δ phase structure, and then deform at a temperature lower than the dissolution temperature of the δ phase to break the reticulated Widmanstattenite δ phase to obtain a spherical δ phase structure, which is surrounded by spherical δ phases The new net blue forms a new fine-grain perimeter, and the fine-grain is further perfected and the grain is further uniformed in the subsequent heat treatment process. Accompanying drawing 2 is the metallographic structure diagram of a kind of embodiment after blanking. Its chemical composition is shown in Table 1. Among them, the alloy is in a non-aging state, the chemical composition is not strictly required, and there is no obvious niobium segregation. The grain size is ASTM5-7, which is a typical example of uneven grain distribution and is necklace-shaped. Process the raw materials according to the flow chart in Figure 1. After the first net blue treatment, a relatively evenly distributed net blue widmanstattenite δ phase (see Figure 3) is obtained, and after being covered with aluminum silicate fiber and 1Cr18Ni9Ti plate Forging or rolling to obtain a spherical δ phase structure (see Figure 4). Finally, the die can be final forged directly on a common press after preheating. In the heat treatment process, a uniform ultrafine grain structure (see accompanying drawing 5) and a delta phase structure (see accompanying drawing 6) are obtained after DA treatment; a uniform ultrafine grain structure (see accompanying drawing 6) is obtained after solution aging treatment Accompanying drawing 7) and delta phase organization structure (see accompanying drawing 8). Accompanying drawing 9 is the situation of another embodiment, that is, the metallographic diagram of uniform grain structure distribution after blanking. Its chemical composition is shown in Table 2, wherein the alloy state, grain size grade, etc. are the same as the previous example. At this time, the net blue-shaped widmansterite δ phase evenly distributed as shown in Figure 3 can be obtained by directly entering the net blue treatment process without pre-deformation treatment. Continue to process according to Fig. 1 flow process, finally still can obtain the uniform ultra-fine grain like accompanying drawing 5 and accompanying drawing 7.
本发明的优点在于无论是预处理还是最终成形都不局限于常规的挤压和公知的挤压比4∶1，而是可以根据产品工艺要求来选择锻造、轧制或挤压等成形工艺。同时，选择易于操作、价格低廉的包套工艺，提出了比较灵活的一次预处理和两次预处理工艺，可以在普通的锤、压力机、液压机、轧机和环轧机上成形。最后，经热处理可以得到直接时效和固溶时效两种状态下ASTM10级以上均匀分布的超细晶组织。本发明揭示了得到超细晶粒的中间坯料组织应是均匀分布的网兰状魏氏体δ相。此外，未经预处理的坯料，虽然利用等温挤压也得不到均匀超细晶粒，以及上述实施例中经预处理后利用普通锻压均能得到均匀超细晶粒的例证，表明本发明的预处理是GH4169锻件、棒材获得超细晶粒组织的必要条件。总之，由于析出网兰状魏氏体δ相，由于合金再结晶充分，采用本发明，使合金性能稳定，较之普通细晶工艺明显地提高了产品质量，改善了高、低周疲劳和抗断裂的能力。而且由于组织均匀，可以大大减少生产检测项目，仅此一项即可提高经济效益24％。本发明即可用于普通锻造，又可用于等温超塑锻造，可操作性强，不仅适用于各航空、航天发动机厂、专业锻造厂，而且可以推广至钢厂，直接生产各种规格优质细晶的GH4169锻件和棒材。本发明简易、合理、实用，适宜于我国企业现状，具有十分可观的经济效益和推广价值。The advantage of the present invention is that both pretreatment and final forming are not limited to conventional extrusion and the known extrusion ratio of 4:1, but forming processes such as forging, rolling or extrusion can be selected according to product process requirements. At the same time, choosing an easy-to-operate and cheap sheathing process, a more flexible one-time pretreatment and two-time pretreatment process is proposed, which can be formed on ordinary hammers, presses, hydraulic presses, rolling mills and ring rolling mills. Finally, after heat treatment, an ultra-fine grain structure uniformly distributed above ASTM grade 10 can be obtained in two states of direct aging and solution aging. The invention discloses that the structure of the intermediate blank for obtaining ultrafine grains should be evenly distributed reticulated widmansterite δ phase. In addition, although the billet without pretreatment can not obtain uniform ultrafine grains by isothermal extrusion, and the example of uniform ultrafine grains that can be obtained by ordinary forging after pretreatment in the above examples shows that the present invention Pretreatment is a necessary condition for GH4169 forgings and bars to obtain ultra-fine grain structure. In a word, due to the precipitation of blue-like widmanstattenite δ phase and the sufficient recrystallization of the alloy, the performance of the alloy is stabilized by adopting the present invention. ability to break. And because the organization is uniform, the production inspection items can be greatly reduced, and this alone can increase the economic benefit by 24%. The invention can be used for ordinary forging and isothermal superplastic forging, and has strong operability. It is not only suitable for various aviation and aerospace engine factories and professional forging factories, but also can be extended to steel factories to directly produce various specifications of high-quality fine grain GH4169 forgings and bars. The invention is simple, reasonable and practical, suitable for the current situation of enterprises in our country, and has very considerable economic benefits and popularization value.
表1
C
S
P
Si
Fe
Cr
Ni
Mo
Ti
Al
B
Nb
0.02
＜0.015
＜0.015
＜0.35
余
17.00
50.00
2.80
0.75
0.70
＜0.006
5.00
Table 1 C S P Si Fe Cr Ni Mo Ti Al B Nb
0.02 <0.015 <0.015 <0.35 Remain 17.00 50.00 2.80 0.75 0.70 <0.006 5.00
表2 C S P Si Fe Cr Ni Mo Ti Al B Nb
0.04
＜0.002
＜0.015
＜0.14
余
18.77
52.31
2.92
1.01
0.61
＜0.006
5.09
Table 2 C S P Si Fe Cr Ni Mo Ti Al B Nb
0.04 <0.002 <0.015 <0.14 Remain 18.77 52.31 2.92 1.01 0.61 <0.006 5.09