They say that instead of government issue or general issue, GI came from the words galvanized iron.

VOA: special.2010.03.07

Iron or steel, 800 million tons, almost a billion tons of steel.

铁或钢，每年8亿吨，几乎接近10亿的钢产量。

麻省理工公开课 - 固态化学导论课程节选

A molar enthalpy of or whatever, iron, as a solid at 298.15 Kelvin is zero.

98。15K下固态铁的，摩尔焓是零。

麻省理工公开课 - 热力学与动力学课程节选

Impurities in glass such as iron can give it a green or brown color.

VOA: special.2009.09.16

The red color is the result of iron oxide or rust.

VOA: special.2009.04.15

It looks something like you'd see when the iron curtain was up or something."

VOA: standard.2010.02.17