1. Copper alloy
一般选用牌号有QA19-2、HPb59-1-1。适用于公称压力小于等于1.6MPa、温度小于等于200度的低压阀门。
2. Carbon steel
Generally choose A5, 35 steel, after nitriding treatment, suitable for ammonia valve with nominal pressure less than or equal to 2.5MPa, low and medium pressure valve for water, steam and other media. A5 steel is suitable for valves whose temperature does not exceed 300 degrees; 35 steel is suitable for valves whose temperature does not exceed 450 degrees. (Note: The actual route proves that the valve stem made of carbon steel nitriding can not solve the corrosion problem well and should be avoided.)
3. Alloy steel
一般选用40Cr、38CrMoA1A、20CrMo1V1A等材料。40Cr经过镀铬处理后，适用于公称压力小于等于32MPa、温度小于等于450度 的水、蒸汽、石油等介质。38CrMoA1A经过氮化处理，能在工作温度540度的条件下承受10MPa的压力，常用于电站阀门上。20CrMo1V1A 经过氮化处理能在工作温度570度的条件下承受14MPa的压力，常用于电站阀门上。
4,
一般选用 2Cr13、3Cr13、1Cr17Ni2、1Cr18Ni12Mo2Ti等材料。2Cr13、3Cr13不锈钢适用于公称压力小于等于32MPa、温度 小于等于450度的水、蒸汽和弱腐蚀性介质，可以通过镀铬、高频淬火等方法强化表面。1Cr17Ni2不锈钢阀、低温阀上，能耐腐蚀性介质。 1Cr18Ni9Ti、1Cr18Ni12Mo2Ti不锈耐酸钢用于公称压力小于等于6.4MPa、温度小于等于600度的高温阀中，也可以用于温度小于 等于-100度的不锈钢阀，低温阀中。1Cr18Ni9Ti能耐硝酸等腐蚀性介质；1Cr18Ni12Mo2Ti能耐醋酸等腐蚀性介质。 1Cr18Ni9Ti、1Cr18Ni12Mo2Ti用于高温阀时，可采用氮化处理，以提高抗擦伤性能。
5. Bearing chrome steel
Select GCr15, which is suitable for ultra-high pressure valves with nominal pressure less than or equal to 300MPa and temperature less than or equal to 300 degrees.
用于制作阀杆的材料较多，还有4Cr10Si2Mo马氏体耐热钢、4Cr14Ni14W2Mo奥氏体耐热钢等。
The valve stem nut and the valve stem are threaded together to directly bear the axial force of the valve stem, and the friction between the plate and the bracket and other valve parts.Therefore, in addition to a certain strength, the valve stem nut also requires the properties of low friction coefficient, no corrosion, and no seizure with the valve stem.
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