Quality Nickel Alloy Casting & Cobalt Alloy Castings factory

When designing a sow mold, it is necessary to combine the thermodynamic properties of metal casting, the service life of the mold, and the quality requirements of the ingot, and focus on the following process parameters: 一. Cavity size and structural parameters•Cavity volume and size: It is necessary to match the weight (usually hundreds to several tons) and shape (such as rectangle, trapezoid) of the target ingot to ensure that the depth and width of the cavity match the volume of the molten metal to avoid incomplete or wasteful ingot molding due to dimensional deviation. •Cavity slope (draft slope): To facilitate demolding, the side wall of the cavity needs to be designed with a certain slope (usually 0.5°-2°). Too small a slope is prone to mold sticking, and too large a slope may affect the dimensional accuracy of the ingot. •Fillet and edge processing: The bottom and corners of the cavity need to be rounded (R angle) to reduce stress concentration and avoid cracks in the mold due to thermal shock; at the same time, prevent shrinkage or cold shut at the corners of the ingot. 二. Thermal and cooling parameters •Wall thickness design: The mold wall thickness needs to be calculated based on the melting point of the casting metal (such as aluminum about 660℃, copper about 1083℃) and heat capacity to ensure that it can withstand the thermal shock of high-temperature molten metal and control the heat dissipation rate through reasonable wall thickness (too thick will cool too slowly, too thin will be easy to deform). •Cooling system layout: If forced cooling (such as water cooling) is used, the position, diameter and spacing of the cooling channel need to be designed. The channel needs to avoid the stress concentration area of ​​the cavity and keep a reasonable distance from the cavity surface (usually ≥50mm) to ensure uniform cooling of the ingot and reduce defects such as shrinkage cavities and cracks. •Thermal expansion compensation: Considering the solidification shrinkage rate of the molten metal (such as the shrinkage rate of aluminum is about 1.3%-2%) and the thermal expansion coefficient of the mold itself, reserve compensation in the cavity size design to avoid ingot size deviation or mold locking. 三. Metal liquid flow and filling parameters •Gate and runner design: The gate position should avoid the metal liquid directly impacting the bottom of the cavity (to prevent splashing and oxidation), and the runner cross section should match the metal liquid flow rate to ensure uniform filling speed (generally controlled at 0.5-1.5m/s) and reduce slag rolls and pores. •Vent structure: Design venting grooves (width 0.1-0.3mm, depth 0.5-1mm) at the top or corner of the cavity to avoid air encapsulation and pores when the metal liquid is filled, and prevent incomplete filling due to gas back pressure. 四. Mechanical performance parameters •Mold strength and rigidity: According to the weight of the ingot (such as 500kg-5 tons) and the static pressure of the molten metal (calculation formula: pressure = molten metal density × height × gravity acceleration), select the appropriate material (such as cast steel, ductile iron) and design the reinforcing rib structure to prevent the mold from deformation or cracking. •Mold release mechanism matching: If mechanical or hydraulic mold release is used, it is necessary to reserve the installation space of the mold release device (such as the ejector hole, the position of the hydraulic cylinder) to ensure that the mold release force (usually 1.5-2 times the weight of the ingot) acts evenly on the bottom of the ingot to avoid damage to the ingot or mold. 五. Material and surface treatment parameters •Material thermal fatigue resistance: For the cyclic process of repeated heating (such as aluminum liquid 660℃) and cooling of molten metal, select materials with moderate thermal conductivity (such as cast steel thermal conductivity of about 40-50W/(m・K)) and high thermal fatigue strength to reduce thermal cracking. •Surface treatment process: Improve surface wear resistance and anti-adhesive aluminum performance through nitriding (hardness up to 50-60HRC), shot peening or coating (such as ceramic coating), reduce demoulding resistance, and reduce erosion and wear of the mold surface by molten metal. These parameters need to be comprehensively optimized in combination with the characteristics of specific casting metals (aluminum, copper, zinc, etc.), production efficiency (such as the number of castings per hour) and quality standards (such as internal flaw detection requirements for ingots), and ultimately achieve the goal of long mold life and high ingot quality. Email: cast@ebcastings.com

What is the application range of sow mold casting different materials? Common materials used to make sow molds include cast iron and cast steel. The following is a detailed introduction and its scope of application: Cast iron: including gray cast iron and ductile iron. Gray cast iron has a lower cost and has certain strength and wear resistance. It is suitable for general aluminum ingot casting scenarios where mold precision and life requirements are not extremely high. Ductile iron has better toughness and strength, can withstand certain thermal and mechanical stresses, and can be used to manufacture medium-capacity sow molds, suitable for casting metals such as aluminum and zinc. Cast steel: such as 1028 cast steel, 8630 cast steel, etc. Cast steel has higher strength, toughness and heat resistance, and can withstand the thermal shock and pressure brought by high-temperature molten metal. 1028 cast steel is often used to manufacture large-capacity sow molds, suitable for large-scale casting of metals such as aluminum ingots. Due to its good comprehensive performance, 8630 cast steel can be used in occasions with high requirements for mold strength and heat resistance, such as the casting of some high-precision alloy ingots. Alloy steel: It is a kind of steel that has been specially alloyed and has excellent strength, wear resistance and heat resistance. It is suitable for high-precision and high-demand alloy steel ingot casting. It is widely used in metallurgy, machinery, aviation, shipbuilding and other industries. It can be used to produce alloy steel ingots required for automobile parts, tools, mechanical parts, etc. Hot working die steel: such as H13 steel. It has good heat resistance, thermal fatigue resistance and wear resistance, and can maintain stable performance in high temperature environment. It is suitable for scenes with high casting temperature and strict requirements on mold thermal performance, such as aluminum alloy, magnesium alloy casting, etc. It can effectively reduce the occurrence of thermal fatigue cracks in the mold during repeated thermal cycles and extend the service life of the mold. Email: cast@ebcastings.com

What are the advantages compared to ceramic balls? At present, there is no public authoritative data to clarify the specific proportion of cast steel balls in the wear-resistant parts market, but grinding balls are an important part of wear-resistant parts. The annual consumption of grinding balls in China has exceeded 2 million tons. Cast steel balls, as a commonly used type of grinding balls, account for a considerable proportion. Especially in the cement crushing industry, cast steel balls have become the main force in the production of steel balls with their high cost performance and potential for sustainable development. Compared with ceramic balls, cast steel balls have the following advantages: Cost advantage: The raw materials and production costs of cast steel balls are relatively low, and the price is more affordable. They are suitable for large-scale industrial applications and can reduce procurement costs for enterprises. Especially for some industries that are more sensitive to costs, such as mining and mineral processing, the cost advantage of cast steel balls makes them more competitive.Good toughness: Cast steel balls have good toughness. Under high impact grinding conditions, they can withstand greater impact forces, are not easy to break, can maintain a good spherical shape, and maintain stable grinding performance. Ceramic balls have relatively poor toughness and are easy to break under high impact environments. Strong adaptability: Cast steel balls are more adaptable to different grinding conditions, and can play a good role in both dry and wet grinding environments. Although ceramic balls are also used in wet grinding, some ceramic balls may be affected in certain special chemical environments, and ceramic balls are generally more suitable for low-impact fine grinding operations. Appropriate density: The density of cast steel balls is moderate, and they can obtain appropriate kinetic energy during the rotation of the mill, which can not only generate sufficient impact force to crush the ore, but also ensure a certain grinding efficiency. In contrast, the density of alumina balls in ceramic balls is low, and the grinding kinetic energy is relatively small. Although high-density ceramic balls such as zirconia beads have large kinetic energy, the wear rate may also be high.Convenient processing and recycling: The production process of cast steel balls is relatively mature, and the processing and manufacturing are relatively convenient. According to different needs, cast steel balls with different performances can be produced by adjusting the chemical composition and heat treatment process. In addition, cast steel balls can be recycled and reused after being scrapped, which conforms to the principle of resource recycling, while ceramic balls are relatively difficult to recycle. email: cast@ebcastings.com

一. Core factors for the selection of cast steel balls for mine dressing Ore properties: hardness, particle size and crushing difficulty 1.Ore hardness:Hard rock (such as iron ore, quartzite, Mohs hardness 6-7): high hardness cast steel balls (HRC 60-65) are required, and the recommended material is high chromium alloy cast steel (chromium content 10%-18%), which has strong wear resistance but toughness needs to be taken into account to avoid excessive crushing and loss.Medium and low hardness ores (such as copper ore, lead-zinc ore, Mohs hardness 4-6): medium chromium cast steel balls (HRC 55-60) or carbon steel balls can be selected, which are more cost-effective. 2.Ore initial particle size:Coarse-grained ore (feed particle size > 50mm): large diameter steel balls (φ80-150mm) are preferred, and crushed by impact force;Fine-grained ore (feed particle size < 20mm): small diameter steel balls (φ30-80mm) are used to improve fineness through grinding.Mill type and working conditionsBall mill specifications:Large mill (diameter>3m): suitable for large diameter steel balls (φ100-150mm), the filling rate is controlled at 30%-40%, and the impact crushing efficiency is enhanced;Small mill (diameter65) is easy to brittle fracture, and HRC 58-63 range is recommended (adjusted according to ore hardness);Impact toughness ≥10J/cm² (tested by Charpy impact test) to avoid crushing under high load conditions.Density and microstructure:Density>7.8g/cm³ (close to the theoretical density of steel), good material density and uniform wear;The microstructure is mainly martensite, supplemented by a small amount of residual austenite, which reduces abrasive spalling. 二. The specific influence of diameter on mineral processing efficiency Diameter Range Advantages Disadvantages Applicable Scenarios φ30-60mm Large grinding area, high fine grinding efficiency, low energy consumption Insufficient impact force, weak coarse crushing ability Secondary grinding, fine-grained ore, high-grade concentrate required φ80-120mm Strong impact force, high efficiency in crushing large ore Low grinding fineness, high energy consumption (larger balls have greater deadweight) First-stage grinding, coarse-grained ore, processing volume priority scenarios φ130-150mm Super large ore crushing (such as raw ore directly into the mill), high single ball crushing ratio Grinding cylinder wear increases, the crushing rate of the steel ball itself increases Super large mill, extremely hard ore coarse crushing 三. Practical suggestions for selection: How to match diameter and efficiency? Precisely match balls according to the stage of ore crushingCase: In the first stage of grinding of an iron ore (the original ore particle size is 80mm, and the hardness is 6.5), a combination of φ100mm accounting for 60% + φ80mm accounting for 40% is selected. Compared with a single φ120mm ball, the grinding efficiency is increased by 15%, and the steel ball loss is reduced by 8%.Logic: The large ball is mainly used for crushing, and the small ball fills the gap, forming a "impact + grinding" composite effect.Dynamically adjust the diameter ratioRegularly check the particle size distribution of the grinding product:If the proportion of + 200 mesh particles is greater than 15%, it means that there are not enough large balls, and large diameter balls need to be added;If the proportion of - 325 mesh particles is greater than 60%, it means that there are too many small balls, and the proportion of small diameter balls can be reduced.Combined energy consumption and cost optimizationFor every 20mm increase in the diameter of the large ball, the power consumption of the mill increases by about 10%-15%, but the processing volume may increase by 5%-8%. It is necessary to calculate the balance point of "cost of steel ball per ton of ore + energy consumption cost". For example: when processing low-value ores, small diameter balls are preferred to reduce energy consumption; large balls can be used appropriately to improve efficiency for high-value ores. 四. Avoiding common misunderstandings Misunderstanding 1: The larger the diameter, the higher the crushing efficiencyCorrection: Large balls are only advantageous when processing coarse-grained ores. In the fine grinding stage, large balls will cause energy waste due to "empty smashing", and the over-crushing rate of the ore will increase (producing invalid fine mud).Misunderstanding 2: The higher the hardness, the betterCorrection: Steel balls with HRC＞63 are prone to surface peeling under low impact conditions. It is recommended to make a comprehensive judgment based on the mill speed (high hardness can be selected when the linear speed is＞2.5m/s) and the ore grinding time. 五. Recommended selection tools SAG/ball mill steel ball ratio calculator: input ore hardness, mill specifications, target particle size, and automatically generate diameter ratio scheme (such as the online tool provided by a certain manufacturer).On-site trial grinding method: first use 3-5 diameter combinations for small batch trial grinding, compare the steel ball consumption per ton of ore, grinding cycle load rate (ideal value 80%-120%), and determine the optimal solution.By accurately matching the cast steel ball diameter with the ore characteristics and mill operating conditions, the unit consumption of steel balls can be controlled within a reasonable range of 0.8-1.5kg/ton of ore while improving the ore dressing efficiency (specific data varies depending on the type of ore).

The fineness of PA11 powder used for wire basket coating is usually selected according to the specific coating process: Micro-coating process: If the micro-coating process is adopted, the powder diameter is generally about 55μm, which is more suitable. Such fineness can control the coating thickness at 100-150μm, and can form a relatively uniform and moderately thick coating on the surface of the wire basket, providing good protection and appearance. Electrostatic spraying: For electrostatic spraying process, a powder diameter of 30-50μm is a better choice. Powders of this fineness can be better adsorbed on the surface of the wire basket under the action of static electricity, and can make the coating thickness reach 80-200μm, which not only ensures the adhesion of the coating, but also can adjust the coating thickness as needed to meet different usage requirements. In addition, the choice of powder fineness may also be affected by factors such as the use environment of the wire basket and the specific requirements for coating performance. For example, if the wire basket needs to be used in a highly corrosive environment, a thicker coating may be required. At this time, if the process permits, a slightly coarser or finer powder can be selected to adjust the coating thickness and density; if the surface smoothness of the coating is very high, a finer powder may be required to obtain a finer surface.