Iron-based alloy powder is commonly used in plasma transfer arc welding (PTAW) due to its excellent mechanical properties and high resistance to corrosion and heat. This type of powder is typically composed of iron as the base metal, along with various alloying elements such as nickel, chromium, molybdenum, and tungsten. Fe Alloy Powder,Stainless Powder,High Temperature Powder,Iron Base Pta Welding Powder Luoyang Golden Egret Geotools Co., Ltd , https://www.xtccarbide.com
1 Soil maturation In general, fruit trees should have 80 to 120 cm soil layers, of which 50% of the root system is distributed in the 0 to 20 cm topsoil layer. Therefore, it is very important to carry out deep-improvement improvement in shallow orchard soils with effective soil layers. Deep plowing can improve the rhizosphere soil permeability and water retention, thereby improving the growth and absorption of fruit tree root environment, promote the growth of the aboveground, improve fruit yield and quality. When deep turning, applying decomposed organic fertilizer, the effect of soil improvement is more obvious. Deep plowing can be performed throughout the year, but it is generally best to combine deep application of the base fertilizer in the fall, and the deep penetrating fertilization immediately impregnates the water, which contributes to the decomposition of organic matter and the absorption of the roots of fruit trees. The depth of ploughing in orchards should be slightly deeper than that in the root distribution area. The orchards without screeds generally have a depth of 80 cm. The orchards in mountainous areas, clayey soil, and shallow soil layers should be deeper; the sandy soils and soil layers should be shallower. .
2 Improvement and preparation of different types of soils Fruit trees require good granule structure, deep soil layer, water, fertilizer, gas, and heat-coordinated soil. Generally, loam, sandy loam soil, and clay loam are suitable for the cultivation of fruit trees, but they have poor physical and chemical properties. For clay and sandy soils, soil improvement is needed.
(1) Cohesive soil has low air content. Mixing sand with organic fertilizers such as crop straws and rice husks with high fiber content can effectively improve the permeability of such soils.
(2) Sandy soils have poor water retention and fertilizer retention, low organic matter content, and dramatic changes in soil surface temperature. Often used "filling silt" (incorporating pond mud, river mud) combined with the addition of organic fertilizer with high fiber content to improve. In recent years, there have been reports of the use of "soil conditioners" abroad. Most of the modifiers are artificially synthesized macromolecular compounds that are applied to sandy soils as a water-retaining agent or to promote the formation of agglomerate structure in the soil.
(3) Improvement of saline-alkali land The main hazard of saline-alkali land is high soil salt content and ion poisoning. When the soil salinity is higher than the soil salt content 0.2%, the concentration of soil solution is too high, the plant root system is difficult to absorb water and nutrients, causing "physiological drought" and nutritional deficiencies. In addition, the saline-alkali soil has a high pH and generally has a pH of 8 or more, which reduces the effectiveness of various nutrients in the soil. The improved technical measures include:
1 Reasonably and reasonably irrigate, wash salt or pressure salt.
2 Apply more organic manure to grow green manure crops such as alfalfa, turfgrass, lotus, Sesbania, lentils, buckwheat, ryegrass, oats, mung beans, etc., to improve the poor structure of the soil and improve the effective nutrients in the soil. Sex.
3 Chemical improvement, application of soil amendments to improve soil pellet structure and water retention performance.
4 cultivating (capillary cut off the surface of the soil), cover the surface, reduce the excessive evaporation of the ground and prevent the salt from rising.
(4) Improvement of viscous soil The hills and mountains south of the Yangtze River in China are mostly red loam soils. The soil is extremely viscous and heavy, easily compacted, with low organic matter content and severely acidic. The improved technical measures include:
1 sand mixing, also known as soil, usually 1 clay + two or three sand.
2 Increase organic fertilizers and widely grown green manure crops to increase soil fertility and regulate pH. But try to avoid the application of acidic fertilizers, available phosphate and lime (750 ~ 1050kg/hm2) and so on. Applicable green fertilizer crops include: Fertilizer radish, milk vetch, rudbeckia, cowpea, faba bean, dolan, rice grass, coriander, rape, etc.
3 Rational farming, no-tillage or less-tillage, soil management such as grassing.
(5) Improvement of sand-wrecked land There are large-area sand-waste lands in the old course of the Yellow River and in the northwest region of China. The soil composition of these areas is mainly sand grains, and organic matter is extremely lacking. The temperature and humidity vary greatly, and there is no ability to retain water and keep fertilizer. The improved technical measures include:
1 Set up a windbreak forest to prevent wind and sand.
2 Excavate irrigation water sources, grow green manure crops on the surface, and increase coverage.
3 soil fill silt combined with the application of organic fertilizer.
4 Apply soil conditioner.
3 Adjustment of Soil pH The pH of the soil has a great influence on the growth and development of various fruit trees, the availability of essential nutrient elements in soil, the activity of soil microorganisms, the ability of roots to absorb water, and the ability to absorb fertilizers, and the effect of harmful substances on the roots, etc. Both are related to soil pH. The optimum soil pH for pears is PH 5.5-8.5.
Phosphorus fertilizer and appropriate amount of lime can be added to the soil during the acid season, or alkaline green manure crops such as wolfberry grass and rapeseed can be used to adjust; when the soil is slightly alkaline, appropriate amount of ferrous sulfate is added, or acidic green manure crops such as alfalfa, grass mulberry, and wheat are planted. Root, ryegrass, etc. to adjust.
The specific composition of the iron-based alloy powder may vary depending on the desired properties and application requirements. For example, adding nickel can increase the strength and toughness of the weld, while chromium enhances the corrosion resistance. Molybdenum and tungsten are often added to improve the high-temperature strength and creep resistance of the weld.
Iron-based alloy powders for PTAW are available in various particle sizes, typically ranging from a few micrometers to several hundred micrometers. The powder is usually fed into the plasma arc through a powder feeder, which ensures a controlled and consistent supply of powder during the welding process.
During PTAW, the powder is melted and deposited onto the workpiece, forming a weld bead. The high energy plasma arc provides the heat necessary to melt the powder and the base metal, creating a strong and durable weld joint.
Overall, iron-based alloy powder for plasma transfer arc welding offers excellent weldability, high mechanical properties, and resistance to corrosion and heat, making it suitable for a wide range of applications in industries such as aerospace, automotive, and power generation.
Soil Improvement Technology of Main Agricultural Technology in 2009
Soil improvement includes soil maturation, improvement of different soil types, and regulation of soil pH.