Introduction to copper & copper alloys - Non-ferrous

Published on 12 October 2023 Leestijd : 4 minutes

Copper and copper alloys and their weldability
Material types
Pure Copper (C)
Copper with small alloy additions (CH)
Copper-zinc alloys / brass (CZ) - Copper-zinc-nickel / nickel silver (NS)
Bronzes – Tin bronze, Phosphor bronze (PB), Silicon bronze and gun metal (G)
Aluminium bronze (CA)
Cupro-Nickels (CN)
Typical applications - silver brazing

See all our Non-ferrous here.

Copper and copper alloys and their weldability

Stainless steel is the generic term for a number of different steels used primarily for their resistance to corrosion. The key element they all share is a certain minimum percentage (by mass) of chromium: 12%. Although other elements, particularly nickel and molybdenum, are added to improve corrosion resistance, chromium is always the deciding factor.

Material types

Copper and copper alloys are grouped by their principal alloying element:

C Pure copper
CH Copper with small alloy additions
CZ Copper-zinc / brass
NS Copper-zinc-nickel / nickel silver
PB Copper-tin-bronze (phosphor bronze alloys also contain phosphorous in their alloy)
G Copper-tin-zinc, gun metal (some alloys contain lead)
CA Copper-aluminium, aluminium bronze (most alloys also contain iron and nickel)
CN Copper-nickel, cupronickel

Pure Copper (C)

Is normally supplied in one of three forms i.e. oxygen bearing, phosphorous deoxidised copper, or oxygen-free copper. For welding jobs, oxygen-free and phosphorous deoxidised copper should be selected as they are more easily welded. TIG and MIG are the preferred welding processes; OAW and SMAW can be used for repair jobs on oxygen bearing tough pitch copper. In order to counteract the high thermal conductivity, He and NO-based gases can be used as an alternative to argon.

Copper with small alloy additions (CH)

Stainless steel can be selected for use compared to other materials for a number of reasons, not just its corrosion resistance. These include:

Aesthetic qualities: it can be polished to a satin or mirror finish
“Dry corrosion” affects steel at higher temperatures where it oxidizes or scales up. Stainless steel is far more resistant to this than ordinary carbon steel and grades such as 310 (25% chromium 20% nickel) were specifically developed for use at high temperatures
Non-contamination of the liquids that stainless steel comes into contact with, because there is no coating to break down and dissolve
Weight savings: since thinner sections and more innovative design structures can be used, with cost savings on foundations and platform weights
Many anti-corrosion coatings are fire hazards or the materials themselves have a low melting point

Copper-zinc alloys / brass (CZ) - Copper-zinc-nickel / nickel silver (NS)

Stainless steel can be selected for use compared to other materials for a number of reasons, not just its corrosion resistance. These include:

Aesthetic qualities: it can be polished to a satin or mirror finish
“Dry corrosion” affects steel at higher temperatures where it oxidizes or scales up. Stainless steel is far more resistant to this than ordinary carbon steel and grades such as 310 (25% chromium 20% nickel) were specifically developed for use at high temperatures
Non-contamination of the liquids that stainless steel comes into contact with, because there is no coating to break down and dissolve
Weight savings: since thinner sections and more innovative design structures can be used, with cost savings on foundations and platform weights
Many anti-corrosion coatings are fire hazards or the materials themselves have a low melting point

Bronzes – Tin bronze, Phosphor bronze (PB), Silicon bronze and gun metal (G)

Tin bronze contains between 1% and 10% Sn, phosphorbronze contains up to 10% phosphorous. Gunmetal is essentially a tin bronze with up to 5% Zn and may also have 5% lead. Silicon bronze contains typically 3% Si and 1% Mn and is the easiest to weld.

Bronzes are weldable using matching filler metals. Gas welding of phosphor bronzes is subject to porosity which can be avoided by using a higher level of deoxidants. Gun metal cannot be welded.

Aluminium bronze (CA)

Stainless steel can be selected for use compared to other materials for a number of reasons, not just its corrosion resistance. These include:

Aesthetic qualities: it can be polished to a satin or mirror finish
“Dry corrosion” affects steel at higher temperatures where it oxidizes or scales up. Stainless steel is far more resistant to this than ordinary carbon steel and grades such as 310 (25% chromium 20% nickel) were specifically developed for use at high temperatures
Non-contamination of the liquids that stainless steel comes into contact with, because there is no coating to break down and dissolve
Weight savings: since thinner sections and more innovative design structures can be used, with cost savings on foundations and platform weights
Many anti-corrosion coatings are fire hazards or the materials themselves have a low melting point

Cupro-Nickels (CN)

Stainless steel can be selected for use compared to other materials for a number of reasons, not just its corrosion resistance. These include:

Aesthetic qualities: it can be polished to a satin or mirror finish
“Dry corrosion” affects steel at higher temperatures where it oxidizes or scales up. Stainless steel is far more resistant to this than ordinary carbon steel and grades such as 310 (25% chromium 20% nickel) were specifically developed for use at high temperatures
Non-contamination of the liquids that stainless steel comes into contact with, because there is no coating to break down and dissolve
Weight savings: since thinner sections and more innovative design structures can be used, with cost savings on foundations and platform weights
Many anti-corrosion coatings are fire hazards or the materials themselves have a low melting point