HASTELLOY B-2 nickel-molybdenum alloy has excellent corrosion resistance in reducing environments HASTELLOY B-3 is an upgraded version of B-2, and has excellent corrosion resistance to hydrochloric acid at any temperature and concentration.Hastelloy is a nickel-based corrosion-resistant alloy, mainly divided into two categories: nickel-chromium alloy and nickel-chromium-molybdenum alloy. Hastelloy has good corrosion resistance and thermal stability, and is mostly used in aviation, chemical fields, etc. The butt welding cap is a component of the container and is connected to the cylinder by welding. (As shown below) According to different geometric shapes, it can be divided into spherical, elliptical, dish-shaped, spherical crown, cone shell and flat cover. Among them, spherical, elliptical, dish-shaped and spherical crown heads are collectively referred to as convex heads. In terms of welding, it is divided into butt welding heads and socket welding heads. It is used for various container equipment, such as storage tanks, heat exchangers, towers, reactors, boilers and separation equipment. The materials include carbon steel (A3, 20#, Q235, Q345B, 16Mn, etc.), stainless steel (304, 321, 304L, 316, 316L, etc.), alloy steel (15Mo3 15CrMoV 35CrMoV45CrMo), aluminum, titanium, copper, nickel and nickel alloys, etc.