公开(公告)号：US6024804A

公开(公告)日：2000-02-15

申请号：US850329

申请日：1997-05-02

申请人： Charles Robert Ferra ,  Mark D. Koepsel

发明人： Charles Robert Ferra ,  Mark D. Koepsel

IPC分类号： C21D5/00 ,  C21D5/02 ,  C22C33/08 ,  C22C37/10 ,  C21D5/06

CPC分类号： C21D5/00 ,  C22C33/08 ,  C22C37/10 ,  C21D5/02

摘要： The invention is a malleable iron comprising about 250 to 400 nodules of graphite per square millimeter as observed in a photomicrograph at 100.times., and a Brinell hardness of about 195 to 550 BHN. Preferably, the malleable iron further comprises sulfur and manganese wherein the manganese is present in an excess amount of at least 2 times the amount of sulfur plus 0.15% and is formed by two separate quenching steps. The invention further comprises a method of preparing a malleable iron having a high nodule count comprising the steps of prenucleating a malleable iron casting at a temperature of about 600 to 900.degree. F. for about 3 to 6 hours; austenitizing the prenucleated casting at about 1680 to 1740.degree. F. for about 3 to 9 hours to form graphite nodules such that the malleable iron has about 250 to 400 nodules per mm.sup.2 ; and quenching the casting to form pearlite and a malleable iron made by this process.

摘要翻译： 本发明是一种可延展的铁，其包括在100x的显微照相中观察到的每平方毫米约250至400个石墨结石，布氏硬度为约195至550 BHN。 优选地，可锻铸铁还包含硫和锰，其中锰以超过硫的量的至少2倍加上0.15％的量存在，并且通过两个单独的淬火步骤形成。 本发明还包括一种制备具有高结核计数的可延展的铁的方法，其包括以下步骤：在约600-900°F的温度下将可锻铸铁铸件脱核约3至6小时; 在约1680至1740°F奥氏体化前核心铸件约3至9小时以形成石墨结核，使得可锻铸铁具有约250至400个结核/ mm 2; 并将铸件淬火以形成珠光体和通过该方法制成的可锻铸铁。