Q355nh grade steel is weathering steel but also belongs to the low-alloy series. The letter Q is the initial letter of yielding pinyin; the number 355 means its yield strength is 355MPa; the letter HN is the initial letter of weathering pinyin. It has the advantages of rust resistance and air corrosion resistance. The use of weathering steel for structural parts has the advantages of corrosion resistance, life extension, thinning and consumption reduction, labor and energy saving.
Q355nh weather resistant steel plate features:
Q355nh weather-resistant plate refers to a low-alloy structural steel with a protective rust layer that resists atmospheric corrosion and can be used to manufacture steel structures such as vehicles, bridges, towers, and containers. Compared with ordinary carbon steel, weathering steel has better corrosion resistance in the atmosphere. Compared with stainless steel, weathering steel has only a small amount of alloying elements, such as phosphorus, copper, chromium, nickel, molybdenum, niobium, vanadium, titanium, etc. The total amount of alloying elements is only a few percent, unlike stainless steel, which can reach 100%. Ten per cent, so the price is relatively low.
Q355nh steel welding requirements:
1. The minimum ambient temperature allowed during welding is as follows:
1) Carbon steel and ordinary low alloy steel (Class A-Ⅰ): -10℃
2) Carbon steel and ordinary low-alloy steel, hot-strength steel and alloy structural steel (Class A-Ⅱ, Ⅲ, B-Ⅰ): 0℃
3) Heat-strength steel and alloy structural steel (B-Ⅱ, Ⅲ class): 5℃
2. When any of the following conditions occurs in the welding environment, effective protective measures should be taken, otherwise welding is prohibited:
1) Manual arc welding wind speed is greater than 8m/s. The wind speed of manual argon arc welding is greater than 2m/s;
2) The relative humidity is greater than 90%;
3) The weldment is splashed with water, rain or fog;
4) When the temperature of the weldment is lower than 0℃.
3. The welding place should be protected from wind, rain and cold.
Q355nh weathering steel application fieldQ355nh weathering steel is mainly used for steel structures exposed to the air (atmosphere) for a long time, such as railways, vehicles, bridges, and towers. Weathering steel is mainly used in the manufacture of some structural parts such as containers, railway vehicles, oil derricks, seaport buildings, oil production platforms, and containers containing hydrogen sulfide corrosive medium in chemical and petroleum equipment.
