1. Alloy 20 Pipe Corrosion Resistance:

• xcellent resistance to general corrosion, pitting, and crevice corrosion in chemicals containing chlorides and sulfuric, phosphoric, and nitric acids.
• Nickel content aids in chloride ion stress and corrosion resistance.
• Additions of Copper and Molybdenum provide resistance to hostile environments, pitting, and crevice corrosion.
• Chromium adds to its resistance of oxidizing environments such as nitric acids.
• Columbium reduces the effects of carbide precipitation.

2. Alloy 20 Pipe Weldability:

• All commonly used welding methods, with the exception of oxyacetylene, can be successfully used.
• The presence of Columbium tends to minimize the precipitation of carbides in the heat-affected zone, so the material may be used in the as-welded condition in most cases.
• Pre-heating is not required.

3.Alloy 20 Pipe Heat Treament:

• Cannot be hardened by heat treatment.
• Stabilized-annealing is done at 1750-1850°F, followed by water quenching.
• Stress relieving can be performed on annealed material up to 950°F.

4. Alloy 20 Pipe Machinability:

Because of Alloy 20′s high work-hardening rate the following are required:

• Only low surface-cutting speeds are possible compared with low-alloy standard austenitic stainless steel.
• Tools should be engaged at all times.
• Heavy feeds are important in getting below the work-hardened ‘skin’.