HIGH-ALLOYED AND ALLOYED STEELS FOR HIGH TEMPERATURE APPLICATIONS:
发布时间: 2020-11-05 15:31
筑结构，工业，汽车工业以及液压领域的低责任零件。另外，它们中的一些还用于生产氮气或空气的高压容器，用于饮用水的管道，冲压零件的生产，航空和铁路零件
Heat-resistant steel grades - chemical composition and characteristics
For elements and components made working at higher temperatures, exceeding 600 ℃, heat-resistant and creep-resistant steels are used.In contrast to boiler steels, heat-resistant and creep-resistant products are used in the working temperature range of 800-1150 ℃. These are generally accepted ranges, and each grade in a particular subgroup has a distinct purpose, creep limit, creep strength, and the environment in which it can operate for a specified period of time. These steels are highly resistant to the corrosive effects of the oxidizing atmosphere at high temperatures.
For the property of heat resistance is responsible, among others, Chromium, for example, in H6S2 - X10CrAl7 steels is in the range of about 5-8%. In the presence of high temperature and difficult environment, oxides appear on the surface of the product due to oxidation, increasing their thickness as the temperature increases. The entire product coverage process only lasts until a sufficient layer is formed to withstand a specific environment that adheres to the intact surface and hardly removes, protecting the other alloying additives inside the product.
In many situations, steel savings contribute to the destruction of the product, as too little alloying material causes the oxides to crack and re-creates the subsequent layers, destroying the product in a relatively short amount of time.
Heat resistance
Resistance to gas, chemical vapors, steam, and reagents is determined by the heat-resistant or gas-corrosion resistance and the temperature, at the same time, exceeding 550 ℃ without taking into account the load that the product is exposed to. Heat-resistant steels contain chromium in the range of 5-30% in chemical composition. In addition to chromium, the most common alloying elements are aluminum – Al, and Silicon – Si, and Titan – Ti, and residual Niobium – Nb, Cerium – Ce, and Nitrogen – N.Some of the heat-resistant steels may, at the same time, serve as creep resistant steels - these alloys with nickel addition with austenitic and austenitic-ferritic structure. The carbon content of the heat resistant steels is as high as 0.30%, thanks to with they have appropriate hardness and abrasion resistance.
It should also be added that silicon and aluminum added to a small extent improve the heat treatment of the material. Due to the structure, we distinguish ferritic steels, heat-resistant austenitic steels, and heat-resistant austenitic-ferritic steels. They are used where, besides high temperature, the products are required as bars, pipes, sheets - resistant to sulfur compounds, engine exhausts, nitriding and carburizing. They are used as steels for carburizing boxes, steels for thermocouple sheaths, rails in ovens, for vacuum chamber parts, for heat-resistant pipes of industrial furnaces.
Creep resistance
In turn, the creep resistance determines the resistance of alloy or high alloy steel to numerous deformations caused by stresses due to operation of the element at high temperatures. Creep-resistant steel grades have an austenitic structure and their chemical composition includes 13 to 28% chromium, and nickel in the range of 8-27%. Depending on the alloy grade, the proportions of these elements are regulated alternately on the basis the intended environment of the particular product (especially in chromium-nickel alloys).Alloys that increase the temperature range of recrystallization and melting, and at the same time increase the level of atomic bonding of the solids network, are Chromium, Titanium, and Silicon, and also Vanadium, Molybdenum, Tungsten, and Cobalt. Carbon content in typically creep-resistant steels in relation to heat-resistant steels is maintained at a negligible level - up to 0.16%, which is relatively common in austenitic structures.
Properties of creep-resistant steels are increased by curing, and as a result of crushing, but by cold plastic deformation and coagulation of the separation of phases they decreases.
Silchrom valve steels - Application and Specification
Chrome and Silicon - CrSi, co-create a duo known as SilChrom Steel, the official name of which is Valve Steels. They are a small group of creep-resistant steels intended for use in aircraft engines, combustion engines of responsible machinery and in automotive parts and valves.Mostly manufactured in the form of forgings for the valves, they are resistant to exhaust gases of aircraft engines, are not erodible by dust from exhaust gases, exhibit a high hardness-to-temperature ratio, do not deform during operation, are easy to form during plastic and mechanical processing, and as few of creep-resistant steels, have a martensitic structure.
Valve steels - chemical composition
The carbon content of this steel group is about 0.4-0.6%, the operating temperature is up to 750 ℃, and as a working product is delivered in a softened state. The addition of tungsten and molybdenum in martensitic valve steels counteracts brittleness and increases safety during the tempering process. Valve steel processing involves hardening at temperatures of 1000-1200 ℃ and tempering at 720-850 ℃ with cooling in water or air.
In the group of valve steel there are also less popular steels with austenitic and austenitic-ferritic structure. In austenitic steels the main additives are Nitrogen, Nickel and Manganese, which together with Chromium create austenitogenic elements. With respect to chromium silicon steels, austenitic steels are characterized by even higher strength at high temperatures.
非合金钢规格
我们公司仅提供该子组中可用材料的一部分。非合金钢用于机械，电器，日用品（如家用电器），金属家具零件，紧固件，一般建筑结构，工业，汽车工业以及液压领域的低责任零件。另外，它们中的一些还用于生产氮气或空气的高压容器，用于饮用水的管道，冲压零件的生产，航空和铁路零件。
我们公司仅提供该子组中可用材料的一部分。非合金钢用于机械，电器，日用品（如家用电器），金属家具零件，紧固件，一般建筑结构，工业，汽车工业以及液压领域的低责任零件。另外，它们中的一些还用于生产氮气或空气的高压容器，用于饮用水的管道，冲压零件的生产，航空和铁路零件。
部分
建筑用非合金钢，用于热改善和渗碳的机加工钢（C10E，C15E，C35E，C45E，C60E） 压力设备用钢（P245GH，P280GH，P305GH，P295GH）， 细晶粒钢 弹簧钢（C55S，C67S，C75S，C85S，C90S，C100S，C125S）， 自动钢（11SMnPb37、11SMn30） 用于冷成型的低碳钢（DC01，DC03，DC04，DC05，DC06，DC07） 热浸镀锌钢或其他表面。
建筑用非合金钢，用于热改善和渗碳的机加工钢（C10E，C15E，C35E，C45E，C60E） 压力设备用钢（P245GH，P280GH，P305GH，P295GH）， 细晶粒钢 弹簧钢（C55S，C67S，C75S，C85S，C90S，C100S，C125S）， 自动钢（11SMnPb37、11SMn30） 用于冷成型的低碳钢（DC01，DC03，DC04，DC05，DC06，DC07） 热浸镀锌钢或其他表面。
化学成分
与普通钢不同，非合金钢在化学成分中的硫和磷含量方面“更清洁”，尽管它们被故意过度充气（例如，以利于机加工）。在化学成分中添加铅-Pb也有助于切割。还应该补充的是，这些材料中有很大一部分存在，并且可能存在于标准化退火中或在标准化轧制条件之后。它们中的一些体积小或被批准用于合金添加剂（例如硅，铜，铬，镍），以改善材料的性能或热处理。它们对材料的特性和性能没有很大的影响（如在合金钢和高合金钢中），但已包含在标准中，并且在较大的零件制造中有利于制造用于特定目的的材料。除铁以外的非合金钢的主要成分是锰和碳。
与普通钢不同，非合金钢在化学成分中的硫和磷含量方面“更清洁”，尽管它们被故意过度充气（例如，以利于机加工）。在化学成分中添加铅-Pb也有助于切割。还应该补充的是，这些材料中有很大一部分存在，并且可能存在于标准化退火中或在标准化轧制条件之后。它们中的一些体积小或被批准用于合金添加剂（例如硅，铜，铬，镍），以改善材料的性能或热处理。它们对材料的特性和性能没有很大的影响（如在合金钢和高合金钢中），但已包含在标准中，并且在较大的零件制造中有利于制造用于特定目的的材料。除铁以外的非合金钢的主要成分是锰和碳。
标准品
上述钢组定义了波兰标准PN-75 / H-84019，PN-88 / H-84020，PN-63 / H-84021，PN-H-84023和EN 10083，EN 10025，EN 10087提供：根据PN-73 / H-92326，PN-EN-13247，PN-93 / H-92329，PN-EN 10132-3，PN-EN 10132-4 进行热处理的弹簧冷轧带材，PN-77 / H-92330，PN-74 / H-92329，PN-87 / H-92143，PN-EN 10131，PN-EN 10130; PN-EN 10139 碳素板，热处理弹簧，根据PN-81 / H-92129，PN-EN 10132-4，PN-EN 10131冷轧 根据PN-81 / H-92121，PN-EN 10130 + A1，PN-94 / H-9220和PN-EN 10029 进行热轧的碳弹簧板，用于热改善 碳无缝钢管热改进根据ГОСТ8731-74，PN-EN 10216-1，PN-EN 10217-1，PN-EN 10216-2，PN-EN 10217-2，PN-EN 10216-4，PN- EN 10217-4 符合PN-85 / H-93001，PN-85 / H-93210，PN-86 / H-93209，PN-EN 10278，PN-87 / H-93200和PN的高温操作压力设备的杆-EN 10060，PN-EN 10277，EN 10016 根据PN-73 / H-84026 进行热改进的碳素扁钢和方钢 根据PN-79 / H-94500，PN-61 / H-94009，PN-EN 10222-2 在高温下工作的压力设备锻件
上述钢组定义了波兰标准PN-75 / H-84019，PN-88 / H-84020，PN-63 / H-84021，PN-H-84023和EN 10083，EN 10025，EN 10087提供：根据PN-73 / H-92326，PN-EN-13247，PN-93 / H-92329，PN-EN 10132-3，PN-EN 10132-4 进行热处理的弹簧冷轧带材，PN-77 / H-92330，PN-74 / H-92329，PN-87 / H-92143，PN-EN 10131，PN-EN 10130; PN-EN 10139 碳素板，热处理弹簧，根据PN-81 / H-92129，PN-EN 10132-4，PN-EN 10131冷轧 根据PN-81 / H-92121，PN-EN 10130 + A1，PN-94 / H-9220和PN-EN 10029 进行热轧的碳弹簧板，用于热改善 碳无缝钢管热改进根据ГОСТ8731-74，PN-EN 10216-1，PN-EN 10217-1，PN-EN 10216-2，PN-EN 10217-2，PN-EN 10216-4，PN- EN 10217-4 符合PN-85 / H-93001，PN-85 / H-93210，PN-86 / H-93209，PN-EN 10278，PN-87 / H-93200和PN的高温操作压力设备的杆-EN 10060，PN-EN 10277，EN 10016 根据PN-73 / H-84026 进行热改进的碳素扁钢和方钢 根据PN-79 / H-94500，PN-61 / H-94009，PN-EN 10222-2 在高温下工作的压力设备锻件
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