阅读说明：本技术 一种热加工态钴基合金棒丝材的制备方法 (Preparation method of hot-working cobalt-based alloy rod wire ) 是由 柏春光 张志强 赵建 杨锐 于 2020-04-23 设计创作，主要内容包括：本发明属于钴基高温合金材料加工技术领域,具体涉及一种热加工态钴基合金棒丝材的制备方法,特别适于热加工态CoCrMo合金棒丝材。该合金的化学成分按质量百分比为：Cr 26.0～30.0%,Mo 5.0～7.0%,Ni≤1.0%,C≤0.14%,Fe≤0.75%,Si≤1.0%,Mn≤1.0%,N≤0.35%,余量为Co。本发明首先通过真空感应熔炼和电渣重熔获得合金铸锭,然后进行均匀化热处理、连续多火次高温锻造、矫直和表面加工等工序,生产出合格的CoCrMo合金棒丝材,为制造医疗器械提供合格原材料。(The invention belongs to the technical field of cobalt-based high-temperature alloy material processing, and particularly relates to a preparation method of a hot-working cobalt-based alloy rod wire, which is particularly suitable for a hot-working CoCrMo alloy rod wire. The alloy comprises the following chemical components in percentage by mass: 26.0-30.0% of Cr, 5.0-7.0% of Mo, less than or equal to 1.0% of Ni, less than or equal to 0.14% of C, less than or equal to 0.75% of Fe, less than or equal to 1.0% of Si, less than or equal to 1.0% of Mn, less than or equal to 0.35% of N, and the balance of Co. According to the invention, firstly, an alloy ingot is obtained through vacuum induction melting and electroslag remelting, and then the procedures of homogenization heat treatment, continuous multi-fire high-temperature forging, straightening, surface processing and the like are carried out, so that the qualified CoCrMo alloy rod wire is produced, and qualified raw materials are provided for manufacturing medical instruments.)

1. A preparation method of a hot-working cobalt-based alloy rod wire is characterized in that the cobalt-based alloy comprises the following chemical components in percentage by mass: 26.0-30.0% of Cr, 5.0-7.0% of Mo, less than or equal to 1.0% of Ni, less than or equal to 0.14% of C, less than or equal to 0.75% of Fe, less than or equal to 1.0% of Si, less than or equal to 1.0% of Mn, less than or equal to 0.35% of N, and the balance of Co;

the method comprises the following steps:

step one, preparing a cobalt-base alloy ingot meeting the requirement of chemical components by adopting vacuum induction melting and electroslag remelting;

step two, carrying out homogenization heat treatment on the cobalt-based alloy cast ingot;

step three, cogging and forging the cobalt-based alloy ingot subjected to the homogenization heat treatment;

fourthly, forging at high temperature to prepare a cobalt-based alloy rod blank or a cobalt-based alloy wire blank;

fifthly, straightening the high-temperature forged bar blank or wire blank;

and step six, turning or centerless grinding the straightened bar blank or wire blank to prepare a finished bar or wire.

2. The method for preparing the hot-processed cobalt-based alloy rod wire according to claim 1, wherein in the first step, metal Co, metal Cr, metal Mo, metal Ni, metal Fe, metal Mn, simple substance Si and simple substance C are required to be adopted, and a finished product ingot is prepared by adopting vacuum induction melting and electroslag remelting processes according to cobalt-based alloy component proportioning.

3. The method for preparing the cobalt-based alloy rod wire in the hot-working state according to claim 1, wherein in the second step, a homogenization heat treatment system is selected to be 1150-1270 ℃, the temperature is kept for 4-24 hours, and the air cooling is carried out to the room temperature.

4. The method for preparing the cobalt-based alloy rod wire in the hot working state according to claim 1, wherein in the third step, an air hammer or a quick forging machine is selected for cogging and forging, the forging temperature is 1150-1230 ℃, the temperature is kept for 3-8 hours, the deformation is 20-40%, and the finish forging temperature is 1100 +/-20 ℃.

5. The method for preparing the cobalt-based alloy rod and wire in the hot working state according to claim 1, wherein in the fourth step, an air hammer, a fast forging machine or a fine forging machine is selected for high-temperature forging, the forging temperature is 1100-1230 ℃, the heat preservation time is 1-5 hours, a rod blank or a wire blank with the diameter of more than 30mm is forged, the deformation per fire is 20-30%, and the finish forging temperature is 1050 +/-20 ℃.

6. The preparation method of the cobalt-based alloy rod and wire in the hot working state according to claim 1 or 5, wherein after the fourth step, the high-temperature forging is further continuously carried out by using a rotary forging machine, the forging temperature is 1050-1150 ℃, the heat preservation time is 1-3 hours, the rod or wire blank with various specifications is forged, the deformation per fire is 10-30%, and the finish forging temperature is 1000 +/-20 ℃.

7. The preparation method of the hot-working cobalt-based alloy rod wire material according to claim 1, wherein the sign of the method is that in the fifth step, a two-roll or multi-roll straightener is selected for straightening, so that the bending degree of a rod blank or a wire blank meets the requirement of a finished product, and the straightening frequency is not more than 2 times; for the subsequent rod blank or wire blank needing to be subjected to centerless grinding, the bending degree needs to be ensured to be less than 0.3 mm/m.

8. The method for preparing cobalt-based alloy rod and wire in a hot-working state according to claim 1, wherein the straightened rod blank or wire blank is subjected to turning or centerless grinding in step six according to the requirements of a finished rod or wire, and the requirements of final size and surface precision meet the requirements of a finished product.

Technical Field

The invention belongs to the technical field of cobalt-based high-temperature alloy material processing, and particularly relates to a preparation method of a hot-working cobalt-based alloy rod wire, which is particularly suitable for a hot-working CoCrMo alloy rod wire.

Background

The cobalt-based alloy has excellent biocompatibility, corrosion resistance, abrasion resistance and fatigue resistance, and is widely used in the medical field. CoCrMo alloy (the nominal component is Co-28Cr-6 Mo) is a cobalt-based alloy which is widely applied at present, and is used for manufacturing various joints, artificial bones, internal and external fixing pieces for orthopedics, connecting rods for internal fixation and lateral bending of spines, false teeth, crowns, inlays and fixing bridges in dental restoration by domestic and foreign medical apparatus enterprises such as Qiangsheng, Meidunli, Shilehui and the like.

Because the CoCrMo alloy has stronger high temperature resistance, higher temperature during hot processing, narrower processing window, strong processing and hardening capacity, larger rheological stress during hot processing and larger hot processing difficulty, domestic CoCrMo alloy products are mostly processed by adopting a casting method. However, the cast CoCrMo alloy has a coarse structure, and although strength can be achieved by adjusting the size and volume fraction of carbides, its plasticity and toughness are low. In addition, looseness and shrinkage cavities can be introduced in the casting process, and the product quality is influenced.

At present, few domestic research reports on the aspect of CoCrMo alloy hot working exist, mature deformation state rod wires are not supplied in the market, so that deformation state CoCrMo alloy rod wires for the domestic medical industry are directly purchased from foreign countries, the purchase period is long, the production requirements of domestic medical instruments cannot be met, and the popularization and application of related products are influenced.

Disclosure of Invention

Aiming at the problem of hot working deformation of the CoCrMo alloy, the invention aims to provide the preparation method of the hot-working cobalt-based alloy rod wire, so that the CoCrMo alloy rod wire meeting the requirements of ASTM F1537 is produced, and the requirements of the domestic medical appliance market are met.

The technical scheme adopted by the invention is as follows:

a preparation method of a hot-working cobalt-based alloy rod wire comprises the following chemical components in percentage by mass: 26.0 to 30.0 percent of Cr26.0 to 7.0 percent of Mo, less than or equal to 1.0 percent of Ni, less than or equal to 0.14 percent of C, less than or equal to 0.75 percent of Fe, less than or equal to 1.0 percent of Si, less than or equal to 1.0 percent of Mn, less than or equal to 0.35 percent of N, and the balance of Co;

the method comprises the following steps:

step one, preparing a cobalt-base alloy ingot meeting the requirement of chemical components by adopting vacuum induction melting and electroslag remelting;

step two, carrying out homogenization heat treatment on the cobalt-based alloy cast ingot;

step three, cogging and forging the cobalt-based alloy ingot subjected to the homogenization heat treatment;

fourthly, forging at high temperature to prepare a cobalt-based alloy rod blank or a cobalt-based alloy wire blank;

fifthly, straightening the high-temperature forged bar blank or wire blank;

and step six, turning or centerless grinding the straightened bar blank or wire blank to prepare a finished bar or wire.

According to the preparation method of the hot-working-state cobalt-based alloy rod wire, in the first step, metal Co, metal Cr, metal Mo, metal Ni, metal Fe, metal Mn, simple substance Si and simple substance C are required to be adopted, and a finished product ingot is prepared by adopting vacuum induction melting and electroslag remelting processes according to cobalt-based alloy component ingredients.

In the second step, a homogenization heat treatment system is selected to be 1150-1270 ℃, the temperature is kept for 4-24 hours, and the material is cooled to room temperature by air.

The preparation method of the hot-working cobalt-based alloy rod wire comprises the third step of selecting an air hammer or a quick forging machine for cogging forging, wherein the forging temperature is 1150-1230 ℃, the temperature is kept for 3-8 hours, the deformation is 20-40%, and the final forging temperature is 1100 +/-20 ℃.

The preparation method of the cobalt-based alloy rod wire in the hot working state comprises the fourth step of forging the cobalt-based alloy rod wire in the hot working state at the high temperature of 1100-1230 ℃ by using an air hammer, a quick forging machine or a precision forging machine for 1-5 hours to obtain a rod blank or a wire blank with the diameter of more than 30mm, wherein the deformation of each fire is 20-30%, and the finish forging temperature is 1050 +/-20 ℃.

After the fourth step, the hot-working cobalt-based alloy rod wire is further forged at 1050-1150 ℃ for 1-3 hours at high temperature by using a rotary forging machine continuously, and is forged into rod blanks or wire blanks of various specifications, wherein the deformation per firing time is 10-30%, and the finish forging temperature is 1000 +/-20 ℃.

In the fifth step, a two-roller or multi-roller straightener is selected for straightening, so that the bending degree of a bar blank or a wire blank meets the requirement of a finished product, and the straightening frequency is not more than 2 times; for the subsequent rod blank or wire blank needing to be subjected to centerless grinding, the bending degree needs to be ensured to be less than 0.3 mm/m.

According to the preparation method of the cobalt-based alloy rod wire in the hot working state, the straightened rod blank or wire blank is subjected to turning processing or centerless grinding in the sixth step according to the requirements of a finished rod or wire, and finally the requirements of the size and the surface precision meet the requirements of a finished product.

The design idea of the invention is as follows:

the invention adopts a special preparation method, firstly obtains alloy cast ingots through vacuum induction melting and electroslag remelting, and then carries out the procedures of homogenization heat treatment, continuous multi-fire high-temperature forging, straightening, surface processing and the like to produce qualified CoCrMo alloy bar wire materials and provide qualified raw materials for manufacturing medical instruments. The preparation method has the design idea that: element segregation existing in the preparation process of the alloy ingot is eliminated through homogenization heat treatment, so that the components of the alloy are uniformly distributed; in addition, by controlling the heating temperature and the deformation amount during hot working, the strength and the grain size of the alloy can be effectively controlled, and the reasonable matching of the strength and the plasticity is realized, so that the CoCrMo alloy wire meeting the requirements of medical instruments is prepared.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention provides a preparation method of a hot-working CoCrMo alloy rod wire, which can be used for producing rod wire products with various specifications and providing qualified raw materials for orthopedic medical instruments.

2. The ingot after vacuum induction melting and electroslag remelting refining is subjected to homogenizing annealing, so that the component uniformity of the alloy is greatly improved, and the texture and the mechanical property of the processed bar and wire material product are uniform and consistent.

3. The wire prepared by the invention has better strong plasticity matching, not only has higher room temperature strength, but also can keep enough room temperature plasticity.

Drawings

FIG. 1 is a microstructure of a 35mm diameter CoCrMo alloy bar prepared in example 1.

FIG. 2 is a microstructure of a Φ 10mm gauge CoCrMo alloy bar prepared in example 2.

FIG. 3 is the microstructure of a 7.0mm gauge CoCrMo alloy bar prepared in example 3.

FIG. 4 is a microstructure of a phi 5.5mm gauge CoCrMo alloy bar prepared in example 4.

Detailed Description

The present invention will be further described with reference to the following examples.