ASTM A216 Standard for Steel Casting Suitable for fusion weld

ASTM A216 covers carbon steel castings for valves, flanges, fittings, or other pressure-containing parts for high-temperature service and of quality suitable for assembly with other castings or wrought-steel parts by fusion welding.

Three grades, WCA, WCB, and WCC, are covered in this specification. Selection will depend upon design and service conditions, mechanical properties, and the high temperature characteristics.

The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

The American Society for Testing and Materials ASTM A216 steel is a medium carbon steel manufactured under a variety of trade names and most commonly used as a casting material for a variety of machine parts.

ASTM A216 is composed primarily of iron, but has a number of additional elements added to give the steel specific properties or increase certain mechanical properties. The steel contains carbon (.25 to .3 percent), chromium (.5 percent), nicklel (.5 percent), molybdenum (.2 percent), copper (.3 percent) and traces of impurities such as sulfur and phosphorous in very small quantities.

Each of these elements lend specific properties. The carbon content is just high enough to allow eat treating and hardening. Chromium and nickle improve the steel's corrosion resistance but aren't present in high enough quantities to make it a stainless steel. Instead, the chromium and nickle increase the steel's toughness. Copper added to the steel increases the strength of the steel.

ASTM A216 has a tensile strength of 60 to 95 kilograms per square inch. Tensile strength is a measurement of the amount of stress or stretching a material can take before breaking. A216 has a yield strength of between 30 and 40 ksi, which measures the amount of pressure it takes for the steel to radically deform. The steel has an elongation of 22 to 24 percent, which is the amount of stretch the steel can handle before breaking.

ASTM A216 is primarily used as a casting material. It is also used as a machine part for heavy equipment. However, A216's properties are not unique enough to require it in any industry, and many other steels with similar properties are used interchangeably.