High Pressure Alloy Steel Seamless Pipes SA 210 GR A1 For Boiler CE Approval

High Pressure Seamless Alloy Steel Pipes SA 210 GR A1 for Boiler

The corrosion resistance of Hastelloy C-4:

Higher molybdenum and chromium content make Hastelloy C-4 alloy can resist various aggressive chemical media, including reducing media, such as phosphoric acid, hydrochloric acid, sulfuric acid, chlorine, chlorine-containing organic or inorganic media. Due to the high nickel content, Hastelloy C-4 can effectively resist chlorine caused due to stress corrosion cracking, and even hot chloride solution.

Hastelloy C-4 is characterized by:

● In the oxidation and reduction status, for most corrosive medium has excellent corrosion resistance.
● In emulsion has excellent resistance to local corrosion.

Standard of Hastelloy C-4: ASTM B674,STM B619 and so on

Hastelloy C-276 Physical properties:

Density: ρ = 8.6g / cm3

melting temperature range: 1335 ~ 1380 ℃

Hastelloy C-4 ISO-V notch test:

Mean ≥120J / cm² at room temperature

≥120J / cm²  -196 ℃

Hastelloy C-4 Heating:

Before the heat treatment and heat treatment process should always be kept clean and pollution-free workpieces.

During the heat treatment can not touch the sulfur, phosphorus, lead and other low melting point metal, otherwise Nicrofer 6616 hMo alloy becomes brittle, should pay attention to remove paint, such as tags, temperature indicating paint, crayons, oil, fuel and other contaminants. Fuel sulfur content as low as possible, the sulfur content of natural gas should be less than 0.1%, heavy oil should be less than 0.5% sulfur content. Electric heating is a better choice, because precise temperature furnace, furnace gas and clean. If the gas furnace gas furnace clean enough, you can choose from.

Furnace gas furnace with a neutral to slightly reducing appropriate, should avoid furnace gas fluctuates between oxidation and reduction, heated by the flame is not burning directly to the workpiece.

Heat treatment:

1. HastelloyC-4 thermal processing temperature range of 1080 ℃ ~ 950 ℃, cooling method for cooling or rapid air cooling.
2. To ensure the best corrosion resistance, thermal processing should be carried out after the heat treatment, the workpiece should be directly added to the warmed heat treatment furnaces. 

Hastelloy C-4 Heat Treatment:

1. Hastelloyc-4 solution treatment temperature range 1050 ℃ ~ 1100 ℃.
2. The cooling method is water quenching, the material thickness of less than 1.5mm can also be used to quickly cooled. 
3. During the heat treatment, the workpiece must be kept clean.

Hastelloy C-4 descaling:

1. Hastelloyc-4 surface oxide and weld around the slag adhesion stronger than stainless steel, is recommended to use fine grain belt or fine grain grinding wheel.
2. Before using HNO3 / HF mixed acid pickling to blasting or grinding the oxide film break.