Columbium. A strong carbide-former, used in type 347 stainless steel for the same reason that titanium is used in type 321. Also found in small amounts in low-alloy structural steels.

• 钶：一种强碳化物形成元素，用在347型号的不锈钢中，就像钛在321型号的不锈钢中的作用一样。在低合金结构钢中也有少量发现。