Raw cast iron spectral analysis standard substance and preparation method thereof

Abstract

The invention relates to the technical field of standard substances, in particular to a raw cast iron spectral analysis standard substance and a preparation method of the raw cast iron spectral analysis standard substance. 0.3 to 3.1% of Si; mn: 0.1 to 1.3%; 0.03% to 1.00% of P; 0.01 to 0.16 percent of S; 0.04 to 0.66 percent of Cr; 0.07% to 0.80% of Ni; cu: 0.05 to 1.85%; 0.08 to 0.65 percent of V; 0.004% to 0.13% of As; b: 0.0004 to 0.04 percent of the total weight of the raw materials 0.01 to 0.040 percent of Ti; 0.004 to 0.065 percent of Co (cobalt); pb: 0.003 to 0.008%; 0.05 to 0.56 percent of Mo; 0.001% to 0.25% of W; 0.002 to 0.07 percent of Alt (aluminum chloride); 0.014% to 0.16% of Sn; 0.03 to 0.15% of Sb; bi: 0.0002% to 0.0095%; 0.01% to 0.06% of Te; mg: 0.007%-0.05%; 0.001% to 0.015% of La; the content of Ce is 0.001 to 0.05 percent; 0.004% of N; 0.0003 to 0.14 percent of Nb (Nitric Oxide); and 0.001% to 0.005% of Zn. According to the method, the standard values of 28 elements are determined, the main components are in gradient distribution, the linear relation of the 25 components is good, and the uncertainty of each element is close to the uncertainty of foreign similar standard substances; the method can be widely applied to analysis and testing of pig iron, alloy cast iron and nodular cast iron, quality monitoring, calibration of measuring instruments, evaluation of measuring methods and material assignment.

Description

Technical Field

[0001] This invention relates to the field of standard reference technology, specifically to a standard reference for the spectral analysis of cast iron and its preparation method. Background Technology

[0002] The internal structure of cast iron can be altered and its mechanical properties improved through forging, modification, and spheroidization. To ensure the reliability and stability of cast iron quality, accurate compositional measurements are essential. These measurements require the calibration of analytical methods, equipment, and results using appropriate standard substances. Standard substances are one or more materials or substances with homogeneous composition and well-defined characteristic values, used to calibrate instruments, evaluate measurement methods, or assign values ​​to materials.

[0003] A search of cast iron reference materials from over twenty countries in the COMAR database, an international standard reference materials database, revealed that countries such as the United States, the United Kingdom, the Czech Republic, and China have information on similar reference materials.

[0004] However, the existing standard reference materials for cast iron only determine or partially determine the standard values ​​of 10 elements, namely C, Si, Mn, P, S, Cr, Ni, Mo, Cu, Ti, and V, while the trace elements such as As, B, W, Al, Sn, Sb, Bi, Mg, La, Ce, N, and Te are not specified, and the gradient distribution of the main component elements is not obvious.

[0005] Based on the current market demand for products such as ductile iron QT500, gray cast iron HT250, HT300, cast pig iron, alloy cast iron, and rare earth magnesium ductile iron, it is necessary to design a standard material for the spectral analysis of cast iron. This material can be widely used for the analysis and testing, quality monitoring, calibration of measuring instruments, evaluation of measurement methods, and material assignment of cast iron, alloy cast iron, and ductile iron. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a standard reference for the spectral analysis of pig iron and its preparation method. The standard reference comprises 13 different components, and standard values ​​for 28 elements have been determined. The principal components exhibit a gradient distribution, and 25 components show good linearity. The uncertainty of each element is close to that of similar standard references from abroad. It can be widely applied to the analysis, testing, and quality monitoring of pig iron, alloy cast iron, and ductile iron; the calibration of measuring instruments; the evaluation of measurement methods; and the assignment of values ​​to materials.

[0007] This invention is achieved through the following technical solution: A standard reference material for the spectroscopic analysis of pig cast iron is provided. The chemical composition and content range of this standard reference material are as follows: C: 2.4~4.8%; Si: 0.3~3.1%; Mn: 0.1~1.3%; P: 0.03~1.00%; S: 0.01~0.16%; Cr: 0.04~0.66%; Ni: 0.07~0.80%; Cu: 0.05~1.85%; V: 0.08~0.65%; As: 0.004~0.13%; B: 0.0004~0.04%; Ti: 0.01~0.040%; Co: 0.004~0.065%. %; Pb: 0.003~0.008%; Mo: 0.05~0.56%; W: 0.001~0.25%; Alt: 0.002~0.07%; Sn: 0.014~0.16%; Sb: 0.03~0.15%; Bi: 0.0002~0.00 95%; Te: 0.01~0.06%; Mg: 0.007~0.05%; La: 0.001~0.015%; Ce: 0.001~0.05%; N: 0.004%; Nb: 0.0003~0.14%; Zn: 0.001~0.005%.

[0008] The standard reference material for spectral analysis of cast iron of the present invention consists of 13 standard reference materials, including: 2 points of QT500, numbered ZBG278c and ZBG278d; 1 point of HT300, numbered ZBG281a; 2 points of HT250, numbered ZBG282b and ZBG282c; 5 points of cast iron, numbered ZBG691, ZBG695, ZBG696, ZBG697 and ZBG698; 2 points of alloy cast iron, numbered ZBG692 and ZBG693; and 1 point of rare earth magnesium ductile iron, numbered ZBG694.

[0009] Specifically, the standard reference material for the spectral analysis of cast iron consists of the following 13 standard reference materials: (1) ZBG278c (QT500), the mass percentages of each component are as follows: C: 3.78±0.05%; Si: 2.32±0.04%; Mn: 0.472±0.005%; P: 0.130±0.003%; S: 0.028±0.005%; Cr: 0.178±0.002%; Ni: 0.161±0.003%; Cu: 0.490±0.003%; V: 0.087±0.004%; As: 0.130±0.003%; B: 0.0091±0.0004%; Ti: 0.016±0.002%; Co: 0.012±0.002%; Mo: 0.170±0.002%; W: 0.132±0.003%; Als: 0.019± 0.002%; Alt: 0.020±0.002%; Sn: 0.047±0.003%; Sb: 0.098±0.006%; Bi: 0.0093±0.0006%; Mg: 0.0 40±0.003%; La: 0.0018±0.0006%; Ce: 0.018±0.003%; Nb: 0.0004±0.0001%; ​​Zn: 0.0023±0.0003%; (2) ZBG278d (QT500), the mass percentages of each component are as follows: C: 3.73±0.05%; Si: 2.38±0.04%; Mn: 0.518±0.004%; P: 0.043±0.004%; S: 0.018±0.003%; Cr: 0.183±0.004%; Ni: 0.134±0.003%; Cu: 0.248±0.004%; V: 0.171±0.005%; As: 0.021±0.002%; B: 0.015±0.002%; Ti: 0.032±0.002%; Co: 0 .0045±0.0005%; Mo: 0.102±0.002%; W: 0.205±0.004%; Als: 0.0083±0.0005%; Alt: 0.0091±0.0005%; Sn: 0.044±0.004%; Sb: 0.030± 0.004%; Bi: 0.0045±0.0005%; Te: 0.043±0.005%; Mg: 0.026±0.004%; La: 0.0015±0.0003%; Ce: 0.018±0.003%; Nb: 0.0010±0.0002%; (3) ZBG281a (HT300), the mass percentage of each component is as follows: C: 3.40±0.03%; Si: 1.73±0.03%; Mn: 0.531±0.004%; P: 0.089±0.004%; S: 0.056±0.004%; Cr: 0.208±0.004%; Ni: 0.182±0.002%; Cu: 0.521±0.006%; V: 0.086±0.004%; As: 0.115±0.005%; B: 0.0088±0.0004%; Ti: 0.014±0. 002%; Co: 0.014±0.002%; Mo: 0.200±0.004%; W: 0.142±0.003%; Als: 0.0033±0.0003%; Alt: 0.0040±0.0003%; Sn: 0.050±0.004% ;Sb: 0.086±0.004%; Bi: 0.0026±0.0004%; Te: 0.060±0.005%; Ce: 0.0013±0.0003%; Nb: 0.0003±0.0001%; ​​Zn: 0.0040±0.0003%; (4) ZBG282b (HT250), the mass percentages of each component are as follows: C: 3.32±0.05%; Si: 1.80±0.03%; Mn: 0.555±0.004%; P: 0.103±0.003%; S: 0.106±0.005%; Cr: 0.316±0.006%; Ni: 0.310±0.005%; Cu: 0.669±0.005%; V: 0.097±0.004%; As: 0.079±0.004%; B: 0.0084±0.0006%; Ti: 0.016±0. 002%; Co: 0.012±0.002%; Mo: 0.312±0.005%; W: 0.115±0.003%; Als: 0.0022±0.0002%; Alt: 0.0029±0.0002%; Sn: 0.051±0.004% ;Sb: 0.084±0.004%; Bi: 0.0082±0.0006%; Te: 0.046±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0005±0.0001%; ​​Zn: 0.0049±0.0005%; (5) ZBG282c (HT250), the mass percentages of each component are as follows: C: 3.40±0.05%; Si: 1.95±0.03%; Mn: 0.818±0.006%; P: 0.072±0.004%; S: 0.055±0.004%; Cr: 0.310±0.005%; Ni: 0.257±0.003%; Cu: 0.460±0.005%; V: 0.126±0.004%; As: 0.049±0.004%; B: 0.011±0.002%; Ti: 0.022±0.0 02%; Co: 0.024±0.002%; Mo: 0.269±0.004%; W: 0.173±0.003%; Als: 0.0014±0.0002%; Alt: 0.0020±0.0003%; Sn: 0.079±0.006% ;Sb: 0.146±0.004%; Bi: 0.0047±0.0005%; Te: 0.057±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0007±0.0001%; ​​Zn: 0.0023±0.0003%; (6) ZBG691 (cast pig iron), the mass percentage of each component is as follows: C: 4.14±0.05%; Si: 1.77±0.02%; Mn: 0.885±0.004%; P: 0.295±0.004%; S: 0.041±0.004%; Cr: 0.334±0.003%; Ni: 0.293±0.003%; Cu: 0.499±0.005%; V: 0.541±0.005%; As: 0.021±0.002%; Ti: 0.085±0.004%; Co: 0.0054±0.0004%; Mo: 0.282±0.004%; Als: 0.0041±0.0003%; Alt: 0.0053±0.0003%; Sn: 0.044±0.004%; Sb: 0.108±0.004%; Bi: 0.0020±0.0003%; (7) ZBG692 (alloy cast iron), the mass percentages of each component are: C: 2.78±0.04%; Si: 3.06±0.04%; Mn: 0.984±0.004%; P: 0.348±0.004%; S: 0.055±0.005%; Cr: 0.653±0.004%; Ni: 0.695±0.004%; Cu: 1.01±0.02%; V: 0.445±0.005%; As: 0.0089±0.0005%; B: 0.039±0.004%; T i: 0.142±0.004%; Co: 0.063±0.004%; Mo: 0.286±0.006%; W: 0.250±0.005%; Als: 0.038±0.003%; Alt: 0.040±0.003%; Sn : 0.051±0.005%; Sb: 0.108±0.003%; Bi: 0.0050±0.0004%; Te: 0.018±0.003%; Nb: 0.139±0.003%; Zn: 0.0025±0.0003%; (8) ZBG693 (alloy cast iron), the mass percentages of each component are: C: 2.43±0.03%; Si: 1.29±0.03%; Mn: 0.932±0.005%; P: 0.191±0.004%; S: 0.081±0.004%; Cr: 0.396±0.004%; Ni: 0.504±0.004%; Cu: 1.84±0.03%; V: 0.088±0.004%; As: 0.0052±0.0004%; B: 0.016±0.002%; Ti: 0.019± 0.003%; Co: 0.025±0.003%; Mo: 0.214±0.003%; W: 0.074±0.004%; Als: 0.024±0.002%; Alt: 0.025±0.002%; Sn: 0.024±0.003 %; Sb: 0.056±0.004%; Te: 0.011±0.003%; Mg: 0.0077±0.0005%; La: 0.0024±0.0003%; Ce: 0.006±0.001%; ​​Nb: 0.067±0.004%; (9) ZBG694 (rare earth magnesium ductile iron), the mass percentage of each component is as follows: C: 3.24±0.04%; Si: 2.11±0.03%; Mn: 0.526±0.004%; P: 0.074±0.004%; S: 0.015±0.003%; Cr: 0.398±0.004%; Ni: 0.203±0.003%; Cu: 0.651±0.005%; V: 0.111±0.003%; As: 0.0042±0.0005%; B: 0.0005±0.0001% ;Ti: 0.157±0.003%; Co: 0.0068±0.0004%; Mo: 0.555±0.005%; W: 0.0013±0.0003%; Als: 0.063±0.004%; Alt: 0.065±0.004 %; Sn: 0.116±0.003%; Mg: 0.046±0.004%; La: 0.014±0.003%; Ce: 0.046±0.005%; Nb: 0.005±0.001%; ​​Zn: 0.0033±0.0003%; (10) ZBG695 (cast pig iron), the mass percentages of each component are as follows: C: 3.99±0.03%; Si: 1.74±0.02%; Mn: 0.965±0.005%; P: 0.327±0.004%; S: 0.054±0.004%; Cr: 0.392±0.004%; Ni: 0.319±0.005%; Cu: 0.504±0.004%; V: 0.218±0.004%; As: 0.027±0.003%; Ti: 0.099±0.004%; Co: 0.0067±0.0004%; Pb: 0.0035±0.0004%; Mo: 0.256±0.004%; W: 0.003±0.001%; ​​Als: 0.014±0.002%; Alt: 0.016±0.002%; Sn: 0.042±0.004%; Sb: 0.067±0.004%; Bi: 0.0020±0.0002%; Te: 0.037±0.005%; Ce: 0.0028±0.0003%; Nb: 0.0026±0.0003%; Zn: 0.0023±0.0003%; (11) ZBG696 (cast pig iron), the mass percentage of each component is as follows: C: 3.57±0.04%; Si: 1.04±0.02%; Mn: 0.668±0.005%; P: 0.980±0.007%; S: 0.153±0.004%; Cr: 0.149±0.003%; Ni: 0.523±0.004%; Cu: 0.819±0.004%; V: 0.490±0.003%; As: 0.050±0.004%; Ti: 0.380±0.004%; Co: 0.0055±0.0004%; Pb: 0 .0072±0.0005%; Mo: 0.105±0.002%; W: 0.0018±0.0003%; Als: 0.029±0.003%; Alt: 0.030±0.003%; Sn: 0.155±0.004%; Sb: 0.042±0.0 04%; Bi: 0.0047±0.0005%; Te: 0.044±0.004%; Ce: 0.0024±0.0003%; N: 0.0040±0.0004%; Nb: 0.0059±0.0006%; Zn: 0.0025±0.0003%; (12) ZBG697 (cast pig iron), the mass percentages of each component are as follows: C: 4.71±0.05%; Si: 0.762±0.005%; Mn: 0.153±0.004%; P: 0.045±0.003%; S: 0.027±0.003%; Cr: 0.500±0.004%; Ni: 0.075±0.004%; Cu: 0.418±0.004%; V: 0.634±0.004%; As: 0.010±0.002%; B: 0.0005 ±0.0001%; ​​Ti: 0.244±0.005%; Co: 0.0062±0.0004%; Pb: 0.0041±0.0004%; Mo: 0.336±0.0 04%; W: 0.0026±0.0004%; Als: 0.036±0.003%; Alt: 0.038±0.003%; Sn: 0.014±0.002%; Bi: 0.0025±0.0004%; Te: 0.048±0.006%; Ce: 0.0033±0.0006%; Nb: 0.0028±0.0005%; Zn: 0.0024±0.0004%; (13) ZBG698 (cast pig iron), the mass percentage of each component is as follows: C: 4.46±0.04%; Si: 0.345±0.004%; Mn: 1.25±0.02%; P: 0.030±0.002%; S: 0.015±0.003%; Cr: 0.042±0.003%; Ni: 0.780±0.006%; Cu: 0.056±0.004%; V: 0.108±0.003%; As: 0.063±0.004%; B: 0.0004±0.0001%; ​​Ti: 0. 041±0.003%; Co: 0.0053±0.0004%; Mo: 0.055±0.005%; W: 0.0029±0.0006%; Als: 0.0072±0.0006%; Alt: 0.0091±0.0006%; S n: 0.105±0.002%; Sb: 0.110±0.005%; Bi: 0.0002±0.0001%; ​​Te: 0.014±0.003%; Ce: 0.0033±0.0005%; Zn: 0.0019±0.0003%.

[0010] A method for preparing a standard reference for spectroscopic analysis of cast iron includes the following steps: S1. Raw Material Preparation: High-quality pure iron, pig iron, rare earth magnesium-silicon ferroalloy, high-purity carbon raiser, and various pure metals and high-quality alloys are used as raw materials. Among them: the purity of pure iron is ≥99.9%; the C content in pig iron is 3.5-4.2%, and the Si content is 1.0-2.0%; the RE content in rare earth magnesium-silicon ferroalloy is 8-12%, the Mg content is 8-10%, and the Si content is 40-45%; the fixed carbon content of the high-purity carbon raiser is ≥98.5%, and the ash content is ≤0.5%; the ferroalloy is selected as low-carbon (C≤0.1%), low-silicon (Si≤1.5%), and low-grade alloy. S2. Smelting: S21. Rough Smelting: A 1.5-ton medium-frequency induction furnace with an acidic lining is used. The temperature is controlled at 1480~1520℃. A batch-by-batch feeding method is adopted. Pure iron and pig iron are added first. After they are completely melted, the following are added in sequence: ferromanganese and ferrochromium alloy elements are added at 1400~1450℃. Rare earth magnesium silicon ferroalloys are added by bell-jar pressing method, with an addition amount of 0.8~1.2% of the weight of the molten iron; high-purity carbon raiser is added at 1450~1480℃; the molten iron tapping temperature is controlled at 1500~1550℃. S22. Refining: Hold at 1540±5℃ for 10-15 minutes; cover the surface of the molten iron with composite refining slag; introduce argon gas for gas stirring at a flow rate of 5-8 L / min; use 10-15 kW electromagnetic stirring at a frequency of 50 Hz. S3. Casting: Water-cooled copper mold casting is adopted, with the cooling water flow rate of 20 - 25 m³ / h; the pouring temperature is controlled at 1300 - 1380 °C; the pouring time is controlled at 45 - 60 seconds; a layered isolation type metal mold is used, and the mold preheating temperature is 200 - 250 °C; immediately spray water for cooling after pouring, and the cooling rate ≥ 50 °C / s; S4. Post-treatment: The casting is annealed at 600 - 650 °C for 2 - 3 h; processed into a Φ33×23 mm standard block by a CNC lathe; the surface roughness is controlled at Ra ≤ 1.6 μm, and the end face parallelism ≤ 0.02 mm; S5. Quality control: A spark direct-reading spectrometer is used for uniformity inspection, and 9 points are detected for each sample; the analysis of variance method is used to evaluate the uniformity, and the F value < F critical value; for the certified value analysis, 8 laboratories jointly certify the value, and uncertainty evaluation is carried out using inhomogeneity, stability, and certification methods.

[0011] Furthermore, in step S2, the addition method of rare earth ferrosilicon magnesium alloy is as follows: The rare earth ferrosilicon magnesium alloy is crushed to a particle size of 5 - 10 mm; loaded into a bell feeder, preheated to 200 - 300 °C; the pressing depth of the bell is 2 / 3 of the molten pool depth; immediately carry out electromagnetic stirring after adding, and the stirring time is 3 - 5 min.

[0012] Furthermore, in step S22, the composition of the composite refining slag covering the molten iron surface is CaO: 40 - 45%, Al2O3: 30 - 35%, SiO2: 20 - 25%, and the covering thickness is 30 - 50 mm.

[0013] Furthermore, in step S3, the water-cooled copper mold includes an upper heat preservation area lined with refractory materials; a middle slow cooling area provided with a graphite sleeve; a lower rapid cooling area with a copper water-cooled jacket; the cooling water channel is designed in a spiral shape.

[0014] Furthermore, in step S4, the CNC lathe performs rough turning and finish turning in sequence, where: during rough turning, the turning speed is 150 - 180 m / min, and the feed rate is 0.2 - 0.3 mm / r; during finish turning, the turning speed is 200 - 250 m / min; the feed rate is 0.1 - 0.15 mm / r.

[0015] The beneficial effects of the present invention: The standard reference material of this invention can be used as a national standard reference material. Comparative experiments were conducted using similar domestic and foreign standard reference materials with similar elemental contents. The comparative data show that this standard reference material not only determined the standard values ​​of elements such as C, Si, Mn, P, S, Cr, Ni, Mo, Cu, Ti, and V, but also assigned values ​​to trace elements such as As, B, W, Al, Sn, Sb, Bi, Mg, La, Ce, N, and Te. The method used for value assignment analysis is accurate and reliable. The uncertainty of each element is close to that of similar foreign standard reference materials, and the uncertainty of some elements is better than that of similar foreign standard reference materials.

[0016] The advantages of the standard reference material for spectral analysis of pig iron of the present invention are: it is diverse, including 13 different components, and standard values ​​of 28 elements have been determined. The main components show a gradient distribution, and 25 components such as C, Si, Mn, P, S, Cr, Ni, Cu, V, As, B, Ti, Mo, Alt, Sn, Sb, Mg, La, and Ce have good linear relationships, all above 0.99. The content of each component has a good gradient distribution. It is widely used in the analysis, testing and quality monitoring of pig iron, alloy cast iron and ductile iron, calibration of measuring instruments, evaluation of measurement methods and assignment of values ​​to materials. Attached Figure Description

[0017] Figure 1 The spectrometer operating curves for the C component in the cast iron spectral analysis standard material of this invention are shown.

[0018] Figure 2 The spectrometer operating curves for the Si content in the standard material for the spectral analysis of cast iron of this invention are shown.

[0019] Figure 3 The spectrometer operating curves for the Mn content in the standard material for the spectral analysis of cast iron of this invention are shown.

[0020] Figure 4 The spectrometer operating curves for the P component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0021] Figure 5 The spectrometer operating curves for the S component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0022] Figure 6 The spectrometer operating curves for the Cr component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0023] Figure 7 The spectrometer operating curves for the Ni component in the cast iron spectral analysis standard material of this invention are shown.

[0024] Figure 8 The spectrometer operating curves for the Cu component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0025] Figure 9 The spectrometer operating curves for the V component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0026] Figure 10 The spectrometer operating curves for the As content in the cast iron standard material used in this invention are shown.

[0027] Figure 11 The spectrometer operating curve is shown for the B component in the standard material for spectral analysis of cast iron of this invention.

[0028] Figure 12 The spectrometer operating curves for the Ti component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0029] Figure 13 The spectrometer operating curves for the Co component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0030] Figure 14 The spectrometer operating curves for Pb content in the standard material for spectral analysis of cast iron in this invention are shown.

[0031] Figure 15 The spectrometer operating curves for the Mo component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0032] Figure 16 The spectrometer operating curves for the W component in the cast iron spectral analysis standard material of this invention are shown.

[0033] Figure 17 The spectrometer operating curves for the Al content in the cast iron spectral analysis standard material of this invention are shown.

[0034] Figure 18 The spectrometer operating curves for the Sn component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0035] Figure 19 The spectrometer operating curves for the Sb component in the standard material for the spectral analysis of cast iron of this invention are shown.

[0036] Figure 20 The spectrometer operating curves for the Bi component in the cast iron spectral analysis standard material of this invention are shown.

[0037] Figure 21 The spectrometer operating curves for the Te component in the standard material for spectral analysis of cast iron of this invention are shown.

[0038] Figure 22 The spectrometer operating curves for the Mg content in the standard material for the spectral analysis of cast iron of this invention are shown.

[0039] Figure 23The spectrometer operating curves for the La component in the cast iron spectral analysis standard material of this invention are shown.

[0040] Figure 24 The spectrometer operating curves for the Ce component in the cast iron spectral analysis standard material of this invention are shown.

[0041] Figure 25 The spectrometer operating curves for the Nb component in the standard material for the spectral analysis of cast iron of this invention are shown. Detailed Implementation

[0042] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution. Example 1:

[0043] A standard reference for the spectral analysis of cast iron consists of 13 standard reference materials, including: 2 points of ductile iron QT500 (numbered ZBG278c and ZBG278d); 1 point of gray cast iron HT300 (numbered ZBG281a); 2 points of gray cast iron HT250 (numbered ZBG282b and ZBG282c); 5 points of foundry pig iron (numbered ZBG691, ZBG695, ZBG696, ZBG697, and ZBG698); 2 points of alloy cast iron (numbered ZBG692 and ZBG693); and 1 point of rare earth magnesium ductile iron (numbered ZBG694). The composition of the 13 standard reference materials is as follows: (1) ZBG278c (ductile iron QT500), the mass percentage of each component is as follows: C: 3.78±0.05%; Si: 2.32±0.04%; Mn: 0.472±0.005%; P: 0.130±0.003%; S: 0.028±0.005%; Cr: 0.178±0.002%; Ni: 0.161±0.003%; Cu: 0.490±0.003%; V: 0.087±0.004%; As: 0.130±0.003%; B: 0.0091±0.0004%; Ti: 0.016±0.002%; Co: 0.012±0.002%; Mo: 0.170±0.002%; W: 0.132±0.003%; Als: 0.019± 0.002%; Alt: 0.020±0.002%; Sn: 0.047±0.003%; Sb: 0.098±0.006%; Bi: 0.0093±0.0006%; Mg: 0.0 40±0.003%; La: 0.0018±0.0006%; Ce: 0.018±0.003%; Nb: 0.0004±0.0001%; ​​Zn: 0.0023±0.0003%; (2) ZBG278d (ductile iron QT500), the mass percentages of each component are as follows: C: 3.73±0.05%; Si: 2.38±0.04%; Mn: 0.518±0.004%; P: 0.043±0.004%; S: 0.018±0.003%; Cr: 0.183±0.004%; Ni: 0.134±0.003%; Cu: 0.248±0.004%; V: 0.171±0.005%; As: 0.021±0.002%; B: 0.015±0.002%; Ti: 0.032±0.002%; Co : 0.0045±0.0005%; Mo: 0.102±0.002%; W: 0.205±0.004%; Als: 0.0083±0.0005%; Alt: 0.0091±0.0005%; Sn: 0.044±0.004%; Sb: 0.030 ±0.004%; Bi: 0.0045±0.0005%; Te: 0.043±0.005%; Mg: 0.026±0.004%; La: 0.0015±0.0003%; Ce: 0.018±0.003%; Nb: 0.0010±0.0002%; (3) ZBG281a (gray cast iron HT300), the mass percentages of each component are as follows: C: 3.40±0.03%; Si: 1.73±0.03%; Mn: 0.531±0.004%; P: 0.089±0.004%; S: 0.056±0.004%; Cr: 0.208±0.004%; Ni: 0.182±0.002%; Cu: 0.521±0.006%; V: 0.086±0.004%; As: 0.115±0.005%; B: 0.0088±0.0004%; Ti: 0.014±0. .002%; Co: 0.014±0.002%; Mo: 0.200±0.004%; W: 0.142±0.003%; Als: 0.0033±0.0003%; Alt: 0.0040±0.0003%; Sn: 0.050±0.004 %; Sb: 0.086±0.004%; Bi: 0.0026±0.0004%; Te: 0.060±0.005%; Ce: 0.0013±0.0003%; Nb: 0.0003±0.0001%; ​​Zn: 0.0040±0.0003%; (4) ZBG282b (gray cast iron HT250), the mass percentages of each component are as follows: C: 3.32±0.05%; Si: 1.80±0.03%; Mn: 0.555±0.004%; P: 0.103±0.003%; S: 0.106±0.005%; Cr: 0.316±0.006%; Ni: 0.310±0.005%; Cu: 0.669±0.005%; V: 0.097±0.004%; As: 0.079±0.004%; B: 0.0084±0.0006%; Ti: 0.016±0. .002%; Co: 0.012±0.002%; Mo: 0.312±0.005%; W: 0.115±0.003%; Als: 0.0022±0.0002%; Alt: 0.0029±0.0002%; Sn: 0.051±0.004 %; Sb: 0.084±0.004%; Bi: 0.0082±0.0006%; Te: 0.046±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0005±0.0001%; ​​Zn: 0.0049±0.0005%; (5) ZBG282c (gray cast iron Ht250), the mass percentage of each component is as follows: C: 3.40±0.05%; Si: 1.95±0.03%; Mn: 0.818±0.006%; P: 0.072±0.004%; S: 0.055±0.004%; Cr: 0.310±0.005%; Ni: 0.257±0.003%; Cu: 0.460±0.005%; V: 0.126±0.004%; As: 0.049±0.004%; B: 0.011±0.002%; Ti: 0.022±0. 002%; Co: 0.024±0.002%; Mo: 0.269±0.004%; W: 0.173±0.003%; Als: 0.0014±0.0002%; Alt: 0.0020±0.0003%; Sn: 0.079±0.006% ;Sb: 0.146±0.004%; Bi: 0.0047±0.0005%; Te: 0.057±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0007±0.0001%; ​​Zn: 0.0023±0.0003%; (6) ZBG691 (cast pig iron), the mass percentage of each component is as follows: C: 4.14±0.05%; Si: 1.77±0.02%; Mn: 0.885±0.004%; P: 0.295±0.004%; S: 0.041±0.004%; Cr: 0.334±0.003%; Ni: 0.293±0.003%; Cu: 0.499±0.005%; V: 0.541±0.005%; As: 0.021±0.002%; Ti: 0.085±0.004%; Co: 0.0054±0.0004%; Mo: 0.282±0.004%; Als: 0.0041±0.0003%; Alt: 0.0053±0.0003%; Sn: 0.044±0.004%; Sb: 0.108±0.004%; Bi: 0.0020±0.0003%; (7) ZBG692 (alloy cast iron), the mass percentages of each component are: C: 2.78±0.04%; Si: 3.06±0.04%; Mn: 0.984±0.004%; P: 0.348±0.004%; S: 0.055±0.005%; Cr: 0.653±0.004%; Ni: 0.695±0.004%; Cu: 1.01±0.02%; V: 0.445±0.005%; As: 0.0089±0.0005%; B: 0.039±0.004%; T i: 0.142±0.004%; Co: 0.063±0.004%; Mo: 0.286±0.006%; W: 0.250±0.005%; Als: 0.038±0.003%; Alt: 0.040±0.003%; Sn : 0.051±0.005%; Sb: 0.108±0.003%; Bi: 0.0050±0.0004%; Te: 0.018±0.003%; Nb: 0.139±0.003%; Zn: 0.0025±0.0003%; (8) ZBG693 (alloy cast iron), the mass percentages of each component are: C: 2.43±0.03%; Si: 1.29±0.03%; Mn: 0.932±0.005%; P: 0.191±0.004%; S: 0.081±0.004%; Cr: 0.396±0.004%; Ni: 0.504±0.004%; Cu: 1.84±0.03%; V: 0.088±0.004%; As: 0.0052±0.0004%; B: 0.016±0.002%; Ti: 0.019± 0.003%; Co: 0.025±0.003%; Mo: 0.214±0.003%; W: 0.074±0.004%; Als: 0.024±0.002%; Alt: 0.025±0.002%; Sn: 0.024±0.003 %; Sb: 0.056±0.004%; Te: 0.011±0.003%; Mg: 0.0077±0.0005%; La: 0.0024±0.0003%; Ce: 0.006±0.001%; ​​Nb: 0.067±0.004%; (9) ZBG694 (rare earth magnesium ductile iron), the mass percentage of each component is as follows: C: 3.24±0.04%; Si: 2.11±0.03%; Mn: 0.526±0.004%; P: 0.074±0.004%; S: 0.015±0.003%; Cr: 0.398±0.004%; Ni: 0.203±0.003%; Cu: 0.651±0.005%; V: 0.111±0.003%; As: 0.0042±0.0005%; B: 0.0005±0.0001% ;Ti: 0.157±0.003%; Co: 0.0068±0.0004%; Mo: 0.555±0.005%; W: 0.0013±0.0003%; Als: 0.063±0.004%; Alt: 0.065±0.004 %; Sn: 0.116±0.003%; Mg: 0.046±0.004%; La: 0.014±0.003%; Ce: 0.046±0.005%; Nb: 0.005±0.001%; ​​Zn: 0.0033±0.0003%; (10) ZBG695 (cast pig iron), the mass percentages of each component are as follows: C: 3.99±0.03%; Si: 1.74±0.02%; Mn: 0.965±0.005%; P: 0.327±0.004%; S: 0.054±0.004%; Cr: 0.392±0.004%; Ni: 0.319±0.005%; Cu: 0.504±0.004%; V: 0.218±0.004%; As: 0.027±0.003%; Ti: 0.099±0.004%; Co: 0.0067±0.0004%; Pb: 0.0035±0.0004%; Mo: 0.256±0.004%; W: 0.003±0.001%; ​​Als: 0.014±0.002%; Alt: 0.016±0.002%; Sn: 0.042±0.004%; Sb: 0.067±0.004%; Bi: 0.0020±0.0002%; Te: 0.037±0.005%; Ce: 0.0028±0.0003%; Nb: 0.0026±0.0003%; Zn: 0.0023±0.0003%; (11) ZBG696 (cast pig iron), the mass percentage of each component is as follows: C: 3.57±0.04%; Si: 1.04±0.02%; Mn: 0.668±0.005%; P: 0.980±0.007%; S: 0.153±0.004%; Cr: 0.149±0.003%; Ni: 0.523±0.004%; Cu: 0.819±0.004%; V: 0.490±0.003%; As: 0.050±0.004%; Ti: 0.380±0.004%; Co: 0.0055±0.0004%; Pb: 0 .0072±0.0005%; Mo: 0.105±0.002%; W: 0.0018±0.0003%; Als: 0.029±0.003%; Alt: 0.030±0.003%; Sn: 0.155±0.004%; Sb: 0.042±0.0 04%; Bi: 0.0047±0.0005%; Te: 0.044±0.004%; Ce: 0.0024±0.0003%; N: 0.0040±0.0004%; Nb: 0.0059±0.0006%; Zn: 0.0025±0.0003%; (12) ZBG697 (cast pig iron), the mass percentages of each component are as follows: C: 4.71±0.05%; Si: 0.762±0.005%; Mn: 0.153±0.004%; P: 0.045±0.003%; S: 0.027±0.003%; Cr: 0.500±0.004%; Ni: 0.075±0.004%; Cu: 0.418±0.004%; V: 0.634±0.004%; As: 0.010±0.002%; B: 0.0005 ±0.0001%; ​​Ti: 0.244±0.005%; Co: 0.0062±0.0004%; Pb: 0.0041±0.0004%; Mo: 0.336±0.0 04%; W: 0.0026±0.0004%; Als: 0.036±0.003%; Alt: 0.038±0.003%; Sn: 0.014±0.002%; Bi: 0.0025±0.0004%; Te: 0.048±0.006%; Ce: 0.0033±0.0006%; Nb: 0.0028±0.0005%; Zn: 0.0024±0.0004%; (13) ZBG698 (cast pig iron), the mass percentages of each component are: C: 4.46±0.04%; Si: 0.345±0.004%; Mn: 1.25±0.02%; P: 0.030±0.002%; S: 0.015±0.003%; Cr: 0.042±0.003%; Ni: 0.780±0.006%; Cu: 0.056±0.004%; V: 0.108±0.003%; As: 0.063±0.004%; B: 0.0004±0.0001%; ​​Ti: 0.041±0.003%; Co: 0.0053±0.0004%; Mo: 0.055±0.005%; W: 0.0029±0.0006%; Als: 0.0072±0.0006%; Alt: 0.0091±0.0006%; Sn: 0.105±0.002%; Sb: 0.110±0.005%; Bi: 0.0002±0.0001%; ​​Te: 0.014±0.003%; Ce: 0.0033±0.0005%; Zn: 0.0019±0.0003%. Example 2:

[0044] A method for preparing a standard reference for spectroscopic analysis of cast iron includes the following steps: S1. Raw material preparation: High-quality pure iron, pig iron, rare earth ferrosilicon magnesium alloy, high-purity carburizer and various pure metals and high-quality alloys are used as raw materials. Among them: the purity of pure iron is ≥99.9%; the C content in pig iron is 3.5 - 4.2%, and the Si content is 1.0 - 2.0%; the RE content in rare earth ferrosilicon magnesium alloy is 8 - 12%, the Mg content is 8 - 10%, and the Si content is 40 - 45%; the fixed carbon content of high-purity carburizer is ≥98.5%, and the ash content is ≤0.5%; ferroalloys are selected as low-carbon (C ≤ 0.1%), low-silicon (Si ≤ 1.5%), and low-grade alloys.

[0045] S2. Melting: S21. Crude melting: A 1.5-ton medium-frequency induction furnace is used, and the furnace lining is an acid furnace lining, with the temperature controlled at 1480 - 1520°C; the batch-by-batch feeding method is adopted. First, pure iron and pig iron are added. After complete melting, the following are added in sequence: ferro-manganese and ferro-chromium alloy elements are added at 1400 - 1450°C, and rare earth ferrosilicon magnesium alloy is added by the bell-jar pressing method, with the addition amount being 0.8 - 1.2% of the weight of the molten iron; high-purity carburizer is added at 1450 - 1480°C; the tapping temperature of the molten iron is controlled at 1500 - 1550°C; S22. Refining: High temperature of 1540 ± 5°C is maintained for 10 - 15 minutes; a composite refining slag is covered on the surface of the molten iron; argon is introduced for gas stirring, with the flow rate being 5 - 8 L / min; electromagnetic stirring of 10 - 15 kW is adopted, with a frequency of 50 Hz.

[0046] S3. Casting: Water-cooled copper mold casting is adopted, with the cooling water flow rate of 20 - 25 m³ / h; the pouring temperature is controlled at 1300 - 1380°C; the pouring time is controlled at 45 - 60 seconds; a layered isolation type metal mold is adopted, and the preheating temperature of the mold is 200 - 250°C; immediately after pouring, water spraying is used for cooling, and the cooling rate is ≥50°C / s.

[0047] S4. Post-treatment: The casting is annealed at 600 - 650°C for 2 - 3 h; it is machined into a Φ33×23 mm standard block by a CNC lathe; the surface roughness is controlled at Ra ≤ 1.6 μm, and the end face parallelism is ≤ 0.02 mm.

[0048] S5. Quality control: A spark direct-reading spectrometer is used for uniformity inspection, and 9 points are detected for each sample; the analysis of variance method is used to evaluate the uniformity, and the F value < the critical F value; for certified value analysis, 8 laboratories jointly conduct the certified value determination, and uncertainty evaluation is carried out using the methods of uniformity, stability, and certified value determination.

[0049] Perform uniformity inspection, stability investigation, and certified value analysis on the cast iron spectral analysis reference material prepared in Example 2, and summarize and process the analysis data.

[0050] I. Uniformity inspection Five standard materials were randomly selected from each point and subjected to radial and longitudinal flaw detection using a CTD10 ultrasonic flaw detector with a 4F probe, starting with a sensitivity of Φ0.5. The tests showed that the internal defects of the sampled standard materials were all less than the equivalent of Φ0.5. Three standard materials were randomly selected from each point for metallographic structure and graphite morphology inspection. The inspection method included inspection of the upper and lower end faces and the half-face. The inspection results of the three end faces were consistent, and no graphite was found in any of the standard materials, indicating that the standard materials were entirely white cast iron. The metallographic structure results are shown in Table 1.

[0051] Table 1 Metallographic Structure Results

[0052] To further examine the longitudinal segregation of the standard material samples, one sample was selected from each furnace, and its axis was non-destructively dissected using wire cutting. The samples were then excited at equal intervals, and their average and range values ​​were statistically analyzed. The results showed that the ranges at both the beginning and end of the sample were less than the allowable error or repeatability r of the corresponding analytical method.

[0053] Twenty samples were randomly selected from the finished product for homogeneity testing. To avoid increased within-group variance due to systematic errors, the excitation order of the 20 samples was randomized. Following the technical specifications of the standard reference materials, the 20 selected samples were numbered sequentially, with the analysis order determined by the random number. Homogeneity testing was performed on three different cross-sectional areas of each sample using a SpectroLab M11 (Germany) photoelectric emission spectrometer. First, traces were taken and fully normalized using a dedicated standard reference material, then type-normalized using a standard reference material of similar content and grade before measurement. The test results were statistically analyzed using the variance method. When the statistic F... <Fα （0.05） When F > Fα, there are no significant differences in data within and between groups, and the homogeneity test is passed. （0.05） If the data within and between groups show significant differences, the homogeneity test fails. Statistical analysis using the variance method shows that the F-values ​​for all elements are less than Fα. （0.05） The uniformity test was passed, and the statistical results of the F-values ​​are shown in Table 2.

[0054] Table 2. Uniformity test F-values ​​(F 0.05 =1.84)

[0055]

[0056] II. Stability Test Within two years, the stability of the standard material was investigated multiple times using the photoelectric emission spectrometry analysis methods of GB / T 43899-2024 and GB / T 24234-2009. The results were statistically tested for stability using the linear fitting method: if the slope |b1| < t α，（n-2）If ×s(b1), the slope is not significant, indicating that the sample is stable. Where: b1 is the slope of the fitted line; s(b1) is the uncertainty of the slope; t α，（n-2） The student distribution is given by n-2 degrees of freedom and a certain confidence level. The stability study data from five measurements between 2022 and 2024 were calculated, showing that the stability study data were consistent over the two years, indicating good sample stability. Furthermore, comparing the stability study results with the uncertainty of the final value, the difference between the two measurements for all stability study items did not exceed the uncertainty of the final value. According to ISO Guide 35, if the following conditions are met: In the formula: This represents the characteristic value of CRM. Let k be the measured observation value, k be the coverage factor, and the confidence level be 95%. Let k=2. The uncertainty of the characteristic value, This refers to measurement uncertainty. Ideally, measurement uncertainty is much smaller than the uncertainty of the characteristic value.

[0057] Comparing the spectral measurements of the reference material in December 2022 and December 2024 with the standard values, the absolute value of the maximum difference was less than or equal to the uncertainty of the given value, and the calculated stability uncertainty was also found to be within acceptable limits. u t The smaller value indicates good stability.

[0058] III. Fixed Value Analysis and Data Summary and Processing In addition to our own unit, we invited domestic units with testing capabilities to participate in the value determination analysis, and selected one or more reliable analytical methods to collaborate on the value determination analysis. Four data points were reported for each element (using the same method), and the range of the four data points in each group was less than the precision of the corresponding analytical method. The standard reference value determination method of this invention was verified using national first-class standard reference materials and nationally published standard solutions. The analytical determination adopted the working curve method, and the measured values ​​of the verification standard reference materials matched the standard values, proving the accuracy and reliability of the method used. The Cochrane criterion was used to verify whether the results of each group were of equal precision, and the conclusion was satisfactory. The Shapiro-Wilke method was used to examine whether the average values ​​conformed to a normal distribution, and the conclusion was satisfactory. The Grubbs method was used to check for outliers in each average value, and the conclusion was satisfactory. When there were no outliers in any group of data, the arithmetic mean and standard deviation of each group of data were calculated. The significant figures of the standard values ​​were rounded according to the method precision in accordance with GB / T 8170-2008, and the standard deviation was rounded up only, aligning the number of decimal places of the standard values ​​with those of the standard values. The standard values ​​and uncertainty statistics of the cast iron standard reference materials are shown in Table 3.

[0059] Table 3. Accepted values ​​and uncertainties (%) of standard reference materials for spectral analysis of pig cast iron

[0060]

[0061]

[0062]

[0063] Note: 1. The number of measurement groups is 8. 2. The uncertainty in the table is expressed as expanded uncertainty, with a coverage factor of 2.

[0064] This series of standard reference materials invited users to test the uniformity and accuracy of the assigned values ​​on a photoelectric emission spectrometer. The results showed that the standard reference materials had good uniformity and accurate values. Linearity was evaluated using a German Spectro Lab M11 spectrometer. The results were applied to cast iron standard reference materials ZBG278c, ZBG278d, ZBG281a, ZBG282b, ZBG282c, ZBG691, ZBG692, ZBG693, ZBG694, ZBG695, ZBG696, ZBG697, and ZBG698, rare earth magnesium cast iron spectral standard reference materials GBW01126a, GBW01127a, GBW01128a, and GBW01129a, and arsenic-containing cast iron spectral standard sample GSB. Twenty-two samples, including 03-1809-2005 (2#, 5#) and ductile iron GBW(E)010463(ZBG271), GBW(E)010464(ZBG272), and GBW(E)010467(ZBG275), were used to fit curves. The linear correlation coefficients of the curves for all 25 elements were above 0.99, as shown in Table 4. The content of each component showed a good gradient distribution. The working curves were plotted as follows... Figures 1-25 As shown.

[0065] Table 4. Linearity and Consistency Assessment of Standard Materials for Spectroscopic Analysis of Pig Cast Iron: Linear Correlation Coefficients

[0066] A search of cast iron reference materials from over twenty countries in the COMAR database revealed information on similar reference materials from countries such as the United States, the United Kingdom, the Czech Republic, and China. This particular reference material is a national-level reference material. Comparative experiments were conducted using similar domestic and international reference materials with comparable elemental content. The comparative data shows that this reference material not only established standard values ​​for elements such as C, Si, Mn, P, S, Cr, Ni, Mo, Cu, Ti, and V, but also assigned values ​​for trace elements such as As, B, W, Al, Sn, Sb, Bi, Mg, La, Ce, N, and Te. The methods used for value assignment analysis are accurate and reliable. The uncertainties of each element are close to those of similar foreign reference materials, and the uncertainties of some elements are even better than those of similar foreign reference materials. The characteristics of the standard reference materials for the spectroscopic analysis of pig iron in this project are: a wide variety, including 13 different components, with standard values ​​determined for 28 elements; the main components exhibit a gradient distribution; and 25 components, including C, Si, Mn, P, S, Cr, Ni, Cu, V, As, B, Ti, Mo, Alt, Sn, Sb, Mg, La, and Ce, show good linear relationships. These materials are widely used in the analysis, testing, and quality monitoring of pig iron, alloy cast iron, and ductile iron; calibration of measuring instruments; evaluation of measurement methods; and assignment of material values. Data comparison is shown in Table 5.

[0067] Table 5 Comparison with similar spectral analysis standard materials at home and abroad (%)

[0068] Referring to similar standard reference materials, the validity period of the standard reference material prepared in this invention is set at fifteen years. The research unit continues to monitor and investigate to ensure the stability of the standard reference material. The composition design and preparation process of the cast iron spectral analysis standard reference material developed in this invention are reasonable. After homogeneity testing and stability investigation, the standard reference material has good homogeneity and stability. The standard values ​​determined by multiple laboratories using accurate and reliable analytical methods based on different principles are accurate and reliable. The development of this standard reference material meets the requirements of JJF1006-1994 "Technical Specification for Primary Standard Reference Materials" and JJF 1343-2022 "Assignment of Standard Reference Materials and Evaluation of Homogeneity and Stability", and has good social and economic benefits.

[0069] In summary, the standard reference materials designed in this invention, through multiple processes including composition design, smelting, casting, homogenization testing, and value determination, have overcome problems such as difficulty in adding trace elements, white iron structure, numerous analytical elements, and difficulty in detecting trace elements. The development of this set of standard reference materials meets the requirements of ISO Guide 17034, ISO Guide 35, ISO Guide 31, and JJF 1006-1994, exhibiting good homogeneity and stability, a good gradient distribution of analytical elements, and good linearity.

Claims

1. A standard reference for spectroscopic analysis of cast iron, characterized in that: The chemical composition and content range of this standard substance are as follows: C: 2.4~4.8%; Si: 0.3~3.1%; Mn: 0.1~1.3%; P：0.03~1.00%； S: 0.01~0.16%; Cr: 0.04~0.66%; Ni: 0.07~0.80%; Cu: 0.05~1.85%; V：0.08~0.65%； As: 0.004~0.13%; B：0.0004~0.04%； Ti: 0.01~0.040%; Co: 0.004~0.065%; Pb: 0.003~0.008%; Mo: 0.05~0.56%; W：0.001~0.25%； Alt: 0.002~0.07%; Sn: 0.014~0.16%; Sb: 0.03~0.15%; Bi: 0.0002~0.0095%; Te: 0.01~0.06%; Mg: 0.007~0.05%; La: 0.001~0.015%; Ce: 0.001~0.05%; N: 0.004%; Nb: 0.0003~0.14%; Zn: 0.001~0.005%.

2. The standard reference material for spectroscopic analysis of cast iron according to claim 1, characterized in that: It consists of the following 13 standard substances: (1) ZBG278c (QT500), the mass percentage of each component is as follows: C: 3.78±0.05%; Si: 2.32±0.04%; Mn: 0.472±0.005%; P: 0.130±0.003%; S: 0.028±0.005%; Cr: 0.178±0.002%; Ni: 0.161±0.003%; Cu: 0.490±0.003%; V: 0.087±0.004%; As: 0.130±0.003%; B: 0.0091±0.0004%; Ti: 0.016±0.002%; Co: 0.012±0.002%; Mo: 0.170±0.002%; W: 0.132±0.003%; Als: 0.019± 0.002%; Alt: 0.020±0.002%; Sn: 0.047±0.003%; Sb: 0.098±0.006%; Bi: 0.0093±0.0006%; Mg: 0.040±0.003%; La: 0.0018±0.0006%; Ce: 0.018±0.003%; Nb: 0.0004±0.0001%; ​​Zn: 0.0023±0.0003%; (2) ZBG278d (QT500), the mass percentages of each component are as follows: C: 3.73±0.05%; Si: 2.38±0.04%; Mn: 0.518±0.004%; P: 0.043±0.004%; S: 0.018±0.003%; Cr: 0.183±0.004%; Ni: 0.134±0.003%; Cu: 0.248±0.004%; V: 0.171±0.005%; As: 0.021±0.002%; B: 0.015±0.002%; Ti: 0.032±0.002%; Co: 0 .0045±0.0005%; Mo: 0.102±0.002%; W: 0.205±0.004%; Als: 0.0083±0.0005%; Alt: 0.0091±0.0005%; Sn: 0.044±0.004%; Sb: 0.030± 0.004%; Bi: 0.0045±0.0005%; Te: 0.043±0.005%; Mg: 0.026±0.004%; La: 0.0015±0.0003%; Ce: 0.018±0.003%; Nb: 0.0010±0.0002%; (3) ZBG281a (HT300), the mass percentage of each component is as follows: C: 3.40±0.03%; Si: 1.73±0.03%; Mn: 0.531±0.004%; P: 0.089±0.004%; S: 0.056±0.004%; Cr: 0.208±0.004%; Ni: 0.182±0.002%; Cu: 0.521±0.006%; V: 0.086±0.004%; As: 0.115±0.005%; B: 0.0088±0.0004%; Ti: 0.014±0. 002%; Co: 0.014±0.002%; Mo: 0.200±0.004%; W: 0.142±0.003%; Als: 0.0033±0.0003%; Alt: 0.0040±0.0003%; Sn: 0.050±0.004% ;Sb: 0.086±0.004%; Bi: 0.0026±0.0004%; Te: 0.060±0.005%; Ce: 0.0013±0.0003%; Nb: 0.0003±0.0001%; ​​Zn: 0.0040±0.0003%; (4) ZBG282b (HT250), the mass percentages of each component are: C: 3.32±0.05%; Si: 1.80±0.03%; Mn: 0.555±0.004%; P: 0.103±0.003%; S: 0.106±0.005%; Cr: 0.316±0.006%; Ni: 0.310±0.005%; Cu: 0.669±0.005%; V: 0.097±0.004%; As: 0.079±0.004%; B : 0.0084±0.0006%; Ti: 0.016±0.002%; Co: 0.012±0.002%; Mo: 0.312±0.005%; W: 0.115±0.003%; Als: 0.0022±0 .0002%; Alt: 0.0029±0.0002%; Sn: 0.051±0.004%; Sb: 0.084±0.004%; Bi: 0.0082±0.0006%; Te: 0.046±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0005±0.0001%; ​​Zn: 0.0049±0.0005%; (5) ZBG282c (HT250), the mass percentages of each component are as follows: C: 3.40±0.05%; Si: 1.95±0.03%; Mn: 0.818±0.006%; P: 0.072±0.004%; S: 0.055±0.004%; Cr: 0.310±0.005%; Ni: 0.257±0.003%; Cu: 0.460±0.005%; V: 0.126±0.004%; As: 0.049±0.004%; B: 0.011±0.002%; Ti: 0.022±0.002%; Co: 0.024±0.002%; Mo: 0.269±0.004%; W: 0.173±0.003%; Als: 0.0014±0. 0002%; Alt: 0.0020±0.0003%; Sn: 0.079±0.006%; Sb: 0.146±0.004%; Bi: 0.0047±0.0005%; Te: 0.057±0.005%; Ce: 0.0012±0.0003%; Nb: 0.0007±0.0001%; ​​Zn: 0.0023±0.0003%; (6) ZBG691 (cast pig iron), the mass percentages of each component are as follows: C: 4.14±0.05%; Si: 1.77±0.02%; Mn: 0.885±0.004%; P: 0.295±0.004%; S: 0.041±0.004%; Cr: 0.334±0.003%; Ni: 0.293±0.003%; Cu: 0.499±0.005%; V: 0.541±0.005%; As: 0.021±0.002%; Ti: 0.085±0.004%; Co: 0.0054±0.0004%; Mo: 0.282±0.004%; Als: 0.0041± 0.0003%; Alt: 0.0053±0.0003%; Sn: 0.044±0.004%; Sb: 0.108±0.004%; Bi: 0.0020±0.0003%; (7) ZBG692 (alloy cast iron), the mass percentages of each component are: C: 2.78±0.04%; Si: 3.06±0.04%; Mn: 0.984±0.004%; P: 0.348±0.004%; S: 0.055±0.005%; Cr: 0.653±0.004%; Ni: 0.695±0.004%; Cu: 1.01±0.02%; V: 0.445±0.005%; As: 0.0089±0.0005%; B: 0.039±0.004%; T i: 0.142±0.004%; Co: 0.063±0.004%; Mo: 0.286±0.006%; W: 0.250±0.005%; Als: 0.038±0.003%; Alt: 0.040±0.003%; Sn : 0.051±0.005%; Sb: 0.108±0.003%; Bi: 0.0050±0.0004%; Te: 0.018±0.003%; Nb: 0.139±0.003%; Zn: 0.0025±0.0003%; (8) ZBG693 (alloy cast iron), the mass percentages of each component are: C: 2.43±0.03%; Si: 1.29±0.03%; Mn: 0.932±0.005%; P: 0.191±0.004%; S: 0.081±0.004%; Cr: 0.396±0.004%; Ni: 0.504±0.004%; Cu: 1.84±0.03%; V: 0.088±0.004%; As: 0.0052±0.0004%; B: 0.016±0.002%; Ti: 0.019± 0.003%; Co: 0.025±0.003%; Mo: 0.214±0.003%; W: 0.074±0.004%; Als: 0.024±0.002%; Alt: 0.025±0.002%; Sn: 0.024±0.003 %; Sb: 0.056±0.004%; Te: 0.011±0.003%; Mg: 0.0077±0.0005%; La: 0.0024±0.0003%; Ce: 0.006±0.001%; ​​Nb: 0.067±0.004%; (9) ZBG694 (rare earth magnesium ductile iron), the mass percentage of each component is as follows: C: 3.24±0.04%; Si: 2.11±0.03%; Mn: 0.526±0.004%; P: 0.074±0.004%; S: 0.015±0.003%; Cr: 0.398±0.004%; Ni: 0.203±0.003%; Cu: 0.651±0.005%; V: 0.111±0.003%; As: 0.0042±0.0005%; B: 0.0005±0.0001% ;Ti: 0.157±0.003%; Co: 0.0068±0.0004%; Mo: 0.555±0.005%; W: 0.0013±0.0003%; Als: 0.063±0.004%; Alt: 0.065±0.004 %; Sn: 0.116±0.003%; Mg: 0.046±0.004%; La: 0.014±0.003%; Ce: 0.046±0.005%; Nb: 0.005±0.001%; ​​Zn: 0.0033±0.0003%; (10) ZBG695 (cast pig iron), the mass percentages of each component are: C: 3.99±0.03%; Si: 1.74±0.02%; Mn: 0.965±0.005%; P: 0.327±0.004%; S: 0.054±0.004%; Cr: 0.392±0.004%; Ni: 0.319±0.005%; Cu: 0.504±0.004%; V :0.218±0.004%; As: 0.027±0.003%; Ti: 0.099±0.004%; Co: 0.0067±0.0004%; Pb: 0.0035±0 .0004%; Mo: 0.256±0.004%; W: 0.003±0.001%; ​​Als: 0.014±0.002%; Alt: 0.016±0.002%; Sn: 0.042±0.004%; Sb: 0.067±0.004%; Bi: 0.0020±0.0002%; Te: 0.037±0.005%; Ce: 0.0028±0.0003%; Nb: 0.0026±0.0003%; Zn: 0.0023±0.0003%; (11) ZBG696 (cast pig iron), the mass percentages of each component are as follows: C: 3.57±0.04%; Si: 1.04±0.02%; Mn: 0.668±0.005%; P: 0.980±0.007%; S: 0.153±0.004%; Cr: 0.149±0.003%; Ni: 0.523±0.004%; Cu: 0.819±0.004%; V: 0.490±0.003%; As: 0.050±0.0 04%; Ti: 0.380±0.004%; Co: 0.0055±0.0004%; Pb: 0.0072±0.0005%; Mo: 0.105±0.002%; W: 0.0018±0.0003% ; Als: 0.029±0.003%; Alt: 0.030±0.003%; Sn: 0.155±0.004%; Sb: 0.042±0.004%; Bi: 0.0047±0.0005%; Te: 0.044±0.004%; Ce: 0.0024±0.0003%; N: 0.0040±0.0004%; Nb: 0.0059±0.0006%; Zn: 0.0025±0.0003%; (12) ZBG697 (cast pig iron), the mass percentages of each component are as follows: C: 4.71±0.05%; Si: 0.762±0.005%; Mn: 0.153±0.004%; P: 0.045±0.003%; S: 0.027±0.003%; Cr: 0.500±0.004%; Ni: 0.075±0.004%; Cu: 0.418±0.004%; V: 0.634±0.004%; As: 0.010±0.002%; B: 0.0005 ±0.0001%; ​​Ti: 0.244±0.005%; Co: 0.0062±0.0004%; Pb: 0.0041±0.0004%; Mo: 0.336±0.0 04%; W: 0.0026±0.0004%; Als: 0.036±0.003%; Alt: 0.038±0.003%; Sn: 0.014±0.002%; Bi: 0.0025±0.0004%; Te: 0.048±0.006%; Ce: 0.0033±0.0006%; Nb: 0.0028±0.0005%; Zn: 0.0024±0.0004%; (13) ZBG698 (cast pig iron), the mass percentages of each component are as follows: C: 4.46±0.04%; Si: 0.345±0.004%; Mn: 1.25±0.02%; P: 0.030±0.002%; S: 0.015±0.003%; Cr: 0.042±0.003%; Ni: 0.780±0.006%; Cu: 0.056±0.004%; V: 0.108±0.003%; As: 0.063±0.004%; B: 0.0004±0.0001%; ​​Ti: 0.041±0.003%; Co: 0.0053±0.0004%; Mo: 0.055±0.005%; W: 0.0029±0.0006%; Als: 0.0072±0.0006%; Alt: 0.0091±0.0006%; Sn: 0.105±0.002%; Sb: 0.110±0.005%; Bi: 0.0002±0.0001%; ​​Te: 0.014±0.003%; Ce: 0.0033±0.0005%; Zn: 0.0019±0.0003%.

3. A method for preparing a standard reference for spectroscopic analysis of pig cast iron according to any one of claims 1 to 2, characterized in that: Includes the following steps: S1. Raw material preparation: It uses high-quality pure iron, pig iron, rare earth magnesium-silicon ferroalloys, high-purity carbon raisers, and various pure metals and high-quality alloys as raw materials, among which: Pure iron purity ≥ 99.9%; Pig iron contains 3.5–4.2% carbon and 1.0–2.0% silicon. Rare earth magnesium-silicon-iron alloys contain 8-12% RE, 8-10% Mg, and 40-45% Si. High-purity carbon raiser has a fixed carbon content ≥98.5% and an ash content ≤0.5%; Ferroalloys with low carbon (C≤0.1%), low silicon (Si≤1.5%), and low grade are selected; S2. Melting: S21. Coarse melting: A 1.5-ton medium-frequency induction furnace is used, with an acidic furnace lining. The temperature is controlled at 1480~1520°C for melting; The batch-by-batch feeding method is adopted. First, pure iron and pig iron are added. After complete melting, the following are added in sequence: Ferromanganese and ferrochromium alloy elements are added at 1400~1450°C. Rare earth ferrosilicon magnesium alloy is added by the bell-jar pressing method, and the addition amount is 0.8~1.2% of the weight of the molten iron; High-purity recarburizer is added at 1450~1480°C; The tapping temperature of the molten iron is controlled at 1500~1550°C; S22. Refining: Maintain at a high temperature of 1540±5°C for 10~15 minutes; cover the molten iron surface with a composite refining slag; introduce argon for gas stirring, with a flow rate of 5~8L / min; adopt electromagnetic stirring of 10~15kW and a frequency of 50Hz; S3. Casting: Water-cooled copper mold casting is adopted, with a cooling water flow rate of 20~25m³ / h; the pouring temperature is controlled at 1300~1380°C; The pouring time is controlled at 45~60 seconds; a layered isolation type metal mold is adopted, and the mold preheating temperature is 200~250°C; immediately spray water for cooling after pouring, and the cooling rate ≥50°C / s; S4. Post-treatment: The castings are annealed at 600~650°C for 2 - 3h; processed into Φ33×23mm standard blocks by a CNC lathe; The surface roughness is controlled at Ra≤1.6μm, and the end face parallelism ≤0.02mm; S5. Quality control: A spark direct-reading spectrometer is used for uniformity inspection, and 9 points are detected for each sample; the analysis of variance method is used to evaluate the uniformity, and the F value < F critical value; for the certified value analysis, 8 laboratories jointly certify the value, and the uncertainty evaluation is carried out using the uniformity, stability, and certified value methods.

4. The standard reference material for spectroscopic analysis of cast iron according to claim 3, characterized in that: In step In S2, the addition method of rare earth ferrosilicon magnesium alloy is as follows: The rare earth ferrosilicon magnesium alloy is crushed to a particle size of 5~10mm; loaded into a bell-jar feeder and preheated to 200~300°C; the bell-jar pressing depth is 2 / 3 of the molten pool depth; Immediately carry out electromagnetic stirring after addition, and the stirring time is 3~5min.

5. The cast iron spectral analysis standard material according to claim 3, characterized in that: In step S22, the composition of the composite refining slag covering the molten iron surface is CaO: 40~45%, Al2O3: 30~35%, SiO2: 20~25%, and the covering thickness is 30~50mm.

6. The standard reference material for spectroscopic analysis of cast iron according to claim 1, characterized in that: In step S3, the water-cooled copper mold includes an upper heat preservation area lined with refractory materials; a middle slow cooling area with a graphite sleeve; a lower rapid cooling area with a copper water-cooled jacket; the cooling water channel is designed in a spiral shape.

7. The cast iron spectral analysis reference material according to claim 1, wherein: In step S4, the CNC lathe performs rough turning and finish turning in sequence. Among them: during rough turning, the turning speed is 150~180m / min, and the feed rate is 0.2~0.3mm / r; during finish turning, the turning speed is 200~250m / min; The feed rate is 0.1~0.15mm / r.

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