阅读说明：本技术 一种解决框架材料c19400产品锈斑缺陷的制备方法 (Preparation method for overcoming rust defect of frame material C19400 product ) 是由 刘景致 续致恒 李素云 苏鹏 冯泽强 于 2020-04-24 设计创作，主要内容包括：本发明涉及消除C19400产品氧化锈斑缺陷的方法,具体为一种解决框架材料C19400产品锈斑缺陷的制备方法。本发明方法把投料过程中铁片和磷铜添加顺序、添加时机、添加量的控制及补加方法进行了调整,投料达到1/3时计算整炉铁片和磷铜需求量,一次性足量添加,满炉后Fe含量不足时补料部分由铁片改为Fe-Cu合金。试验6个批次,除个别头尾有灰色质点析出外,其余料面符合要求。相同工艺又试验6个批次,效果稳定,料面符合质量要求。(The invention relates to a method for eliminating the defect of oxidation rust spots of a C19400 product, in particular to a preparation method for solving the defect of the rust spots of a frame material C19400 product. The method adjusts the adding sequence, adding time and adding amount of iron sheets and phosphorus copper in the feeding process, calculates the required amount of the iron sheets and the phosphorus copper in the whole furnace when the feeding reaches 1/3, adds the iron sheets and the phosphorus copper in a sufficient amount at one time, and changes the supplemented material part from the iron sheets to Fe-Cu alloy when the Fe content is insufficient after the furnace is full. The test of 6 batches shows that the material surface meets the requirements except that the individual heads and tails have grey spots to be analyzed. The same process is used for testing 6 batches, the effect is stable, and the charge level meets the quality requirement.)

1. A preparation method for solving rust stain defects of a frame material C19400 product is characterized by comprising the following steps: the preparation method comprises the following feeding sequence: 1-level copper alloy/1-level pure copper/part of 1-level copper alloy scraps-iron pieces and phosphorus copper alloy-the rest of 1-level copper alloy scraps-2-level copper alloy/2-level copper alloy scraps;

melting completely after the feeding is finished, raising the temperature to 1200-; when the smelting furnace is not added with the iron-copper alloy after the first sampling analysis, standing for 10-15min, and switching to a heat preservation furnace if other components are qualified, wherein the temperature of the heat preservation furnace is controlled to 1190-; when the iron-copper alloy is added after the first sampling analysis of the smelting furnace, the smelting furnace needs to be kept stand for 25-30min, the converter can be changed into a heat preservation furnace if the other components are qualified, and the temperature of the converter is controlled to 1190-1210 ℃;

the power of the heat preservation furnace is adjusted to be below 100kw before the converter, the temperature is controlled to be 1190-.

2. The preparation method for solving the rust defect of the frame material C19400 product, as claimed in claim 1, wherein: when the iron sheet is added, the smelting furnace is powered off, then the iron sheet is added to the surface of the molten copper to enable the molten copper to be fully contacted with the molten copper, and then the molten copper is covered by the residual 1-level copper alloy scraps and then the molten copper is supplied with power.

Technical Field

The invention relates to a method for eliminating rust defects of a C19400 product, in particular to a preparation method for solving the rust defects of the frame material C19400 product.

Background

The C19400 lead frame electronic copper strip is a copper-iron-phosphorus series alloy, has good electric and heat conducting properties, and has high strength, hardness, softening temperature resistance, corrosion resistance, stress corrosion resistance and the like. The strip has high precision, good plate shape and no residual stress, and is used for the socket connector in the electronic industry, the lead frame material of a large-scale integrated circuit and the like. The C19400 product is formed by smelting 1-grade copper alloy, 1-grade pure copper, 1-grade copper alloy scraps, 2-grade copper alloy and 2-grade copper alloy scraps and adding iron sheets and phosphorus, wherein the ratio of 1-grade pure copper: the surface is bright, has no oxidation, no dirt and coating on the surface and no oil stain. 1-grade copper alloy: single mark 194, no oxidation, no oil stain and no coating on the surface. 2-grade copper alloy: single designation 194, allows for oxidation, oil contamination and coatings on the surface. Grade 1 copper alloy scrap: single grade 194 copper alloy scrap, free of impurities, oil and water. Grade 2 copper alloy scrap: single grade 194 copper alloy scrap, inclusion < 5%, allows for a small amount of oil or water. But it will find a lot of oxidation rusty spot quality problems in the course of production and use, and the samples produced in the subsequent process and fed back by the client are observed under 200 times microscope: the samples were compared before and after grinding, and it was found that grey particles remained after grinding, confirming that the defect was caused by internal tissue structure. Further confirmation is carried out by a scanning electron microscope, components are beaten according to specified points, and the conclusion is that the casting is a problem, and the phenomenon is caused by iron enrichment. The test results are shown in FIG. 2: two points are made in the depressed area, wherein the iron content at the 1 st point is 51 percent, the iron content at the second point is 13.5 percent, and the calcium content is 12.1 percent. Therefore, the C19400 product has the defect of rust spot in the subsequent process due to the local Fe enrichment caused by the non-uniform distribution of Fe element in the casting process.

Disclosure of Invention

The main control of Fe content change in the smelting process is the iron sheet, whether the distribution of Fe element in the product is uniform or not directly influences the performance of the product, the Fe content of the C19400 alloy is high, the proportion of Fe is 2.1% -2.6%, the melting point of Cu is 1083 ℃, the melting point of Fe is 1535 ℃, the iron sheet is directly added, the control difficulty of the production process is high, the slag bonding and burning loss are large, the component control is difficult, and Fe is not easy to melt and is not easy to distribute uniformly in Cu. Therefore, the invention starts to improve from two aspects of the sufficiency of Fe dissolved in Cu and the uniformity of mixing, adopts a reasonable smelting mode to ensure that Fe is fully dissolved in molten copper, and avoids the occurrence of local Fe element enrichment so as to avoid the occurrence of rusty spots.

The invention is realized by adopting the following technical scheme: a preparation method for solving the rust defect of a frame material C19400 product is characterized in that the feeding sequence is adjusted to be 1-level copper alloy/1-level pure copper/part of 1-level copper alloy scraps, required iron sheets and phosphorus copper alloy are added, and the rest 1-level copper alloy scraps are 2-level copper alloy/2-level copper alloy scraps.

After the smelting furnace finishes the first complete feeding, the temperature is raised to 1200-1230 ℃, then sampling and analyzing are carried out, the power is cut off for 5-10 minutes, the heat preservation power is sent to 100-kw after the time is up, whether the second batch is fed is determined according to the test result, and the quality content of Fe in the C19400 alloy is required to be controlled according to 2.10% -2.35%. After the first test of the smelting furnace, only allowing to add iron-copper alloy when the iron components need to be adjusted, and standing for 10-15min when the iron-copper alloy is not added after the first sampling test of the smelting furnace, wherein other components are qualified and can be converted into a converter; when the iron-copper alloy is added after the first sampling and testing of the smelting furnace, the smelting furnace needs to be kept stand for 25-30min, the other components are qualified, and the temperature of the converter is controlled at the middle-lower line (1190-.

The heat preservation furnace does not allow any intermediate alloy to be added, the power is adjusted to be below 100kw before the converter, the temperature is controlled at the lower heat preservation temperature line (1190-.

When the iron sheets are added, the smelting furnace is powered off, then the iron sheets are added into the surface of the molten copper to be fully contacted, and then the residual 1-level copper alloy scraps are used for covering the molten copper and then supplying power.

The invention adjusts the adding sequence, adding time and adding amount of iron sheets and phosphorus copper in the feeding process, calculates the required amount of the iron sheets and the phosphorus copper in the whole furnace when the feeding reaches the total amount of 1/3 (the feeding proportion of 1-level copper alloy/1-level pure copper/part of 1-level copper alloy scraps), adds the iron sheets and the phosphorus copper in a sufficient amount at one time, and changes the supplemented part from the iron sheets to Fe-Cu alloy when the Fe content is insufficient after the furnace is full. The test of 6 batches shows that the material surface meets the requirements except that the individual heads and tails have grey spots to be analyzed.The same process is used for testing 6 batches, the effect is stable, and the charge level meets the quality requirement. The earlier adding sequence of the iron sheets ensures that the Fe has sufficient dissolving and mixing time in the Cu solution; p has low melting point, is easy to volatilize and has larger loss, so the P is generally added in the later stage during smelting, but under the condition that the iron sheet is added firstly and then the P is added later, the iron in the melt is oxidized to generate oxide, the P added later and the iron are difficult to react, so the fine and stable Fe is promoted after the Cu-P alloy and the iron sheet are added simultaneously₂P、Fe₃And (4) generation of a P compound. And finally, the smelting furnace is powered off and then powered on, and the holding furnace is firstly powered on with high power and then powered on with low power to fully boil again, 6 batches of tests are carried out, the effect is stable, and the charge level meets the quality requirement.

According to the Cu-Fe phase diagram, the solubility change of Fe in copper and the characteristics of alloy components, the smelting furnace and the heat preservation furnace for producing the C19400 product ensure the uniform effect of the components by increasing high-power stirring strength and stirring time, and meet the requirements of users through multiple test tracking.

Drawings

FIG. 1 shows the product viewed under a 200-fold microscope.

FIG. 2 is a scanning electron microscope image of the product.

Detailed Description