How to perform welding of Hastelloy columns?

Hastelloy column is a kind of seamless steel pipe, its performance is much higher than the general seamless steel pipe, its high-temperature resistance, low-temperature resistance, corrosion resistance is the ordinary seamless steel pipe that can not be compared. So what kind of charm do Hastelloy columns have to prompt users to choose it?

Here is the content list:

l What are the heat treatment processes for Hastelloy columns?

l How to perform welding of Hastelloy columns?

l What is the corrosion resistance of the Hastelloy column?

What is the corrosion resistance of the Hastelloy column?

1.Hastelloy columns have excellent corrosion resistance to most corrosive media in both oxidizing and reducing atmospheres.

2.Hastelloy column has excellent resistance to pitting, crevice corrosion, and stress corrosion. The higher Mo and Cr content enable the alloy to resist chloride ion corrosion, and the W element further improves the corrosion resistance. Also, Hastelloy C-276 is one of only a few materials that resist corrosion by moist chlorine, hypochlorite, and chlorine dioxide solutions, and has significant corrosion resistance to high concentrations of chloride salt soluble waves such as ferric chloride and copper chloride. It is suitable for all concentrations of sulfuric acid solutions and is one of the few materials that can be used in hot concentrated sulfuric acid solutions.

How to perform welding of Hastelloy columns?

Hastelloy column welding properties and ordinary austenitic stainless steel, before using a welding method for Hastelloy column welding, it is necessary to take measures to minimize the corrosion resistance of the weld and heat-affected zone, such as tungsten gas shielded welding ( GTAW ), metal electrode gas shielded welding ( GMAW ), submerged arc welding or some other welding methods can make the weld and heat-affected zone corrosion resistance is minimized. method. But for such as oxyacetylene welding and other welding methods that may increase the material weld and heat-affected zone carbon or silicon content is not suitable for use.

Regarding the choice of welded joint form of Hastelloy columns, you can refer to the ASME Boiler and Pressure Vessel Code for Hostel C- 276 alloy welded joints of successful experience. The welding process should be carried out at a suitable heat input rate to prevent thermal cracking.

What are the heat treatment processes for Hastelloy columns?

Solution heat treatment of Hastelloy columns consists of two processes:

( 1 ) at 1040 ° C ~ 1150 ° Cheating; (2 ) within two minutes of rapid cooling to the color state, so that the treated material has very good corrosion resistance.

Therefore, only the stress relief heat treatment of Hastelloy columns is not effective. Before the heat treatment, the alloy surface should be cleaned of all dirt such as oil and dirt that may produce carbon elements during the heat treatment. Hastelloy column surface in welding or heat treatment will produce oxides, so that the Cr content of the alloy is reduced, affecting the corrosion resistance, so the surface should be cleaned. You can use a stainless steel wire brush or grinding wheel, then dip into the appropriate proportion of nitric acid and a hydrofluoric acid mixture of pickling, and finally rinsed with clean water.

Nanjing Suntech Metal Equipment Co., Ltd. has carried out a large number of tests before the official launch of the Hastelloy column to ensure quality, always adhere to the "quality as the root, to the market, innovation and development" business purposes, commitment to "quality, excellence, customer satisfaction is our eternal pursuit" business service concept, Continuously provide our customers with better products and more cost-effective services.