Spheroidal graphite cast iron member having improved mechanical strength
hand method of producing same
    1.
    发明授权
    Spheroidal graphite cast iron member having improved mechanical strength hand method of producing same 失效
    具有改进的机械强度手球法的球墨铸铁件

    公开(公告)号:US5346561A

    公开(公告)日:1994-09-13

    申请号:US22623

    申请日:1993-02-25

    IPC分类号: C21D5/00 C22C37/04

    摘要: The spheroidal graphite cast iron member having a surface layer portion mostly composed of a ferrite phase and having a thickness of at least 1 mm, and an inner portion composed of a pearlite phase and a ferrite phase, the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15% is produced by (a) pouring a spheroidal graphite cast melt into a casting mold; (b) removing the casting mold by shake-out after the completion of solidification of the melt, while substantially the entire portion of the resulting cast iron product is still at a temperature of its A.sub.1 transformation point or higher; (c) when the temperature difference between the surface layer portion and the inner portion has become 40.degree.-60.degree. C., introducing the cast iron product into a uniform-temperature furnace kept at 750.degree.-900.degree. C., where the cast iron product is held for such a time period as to produce the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15%; and (d) transferring the cast iron product into a cooling furnace to cool the cast iron product at a cooling speed of 15.degree.-100.degree. C./min.

    摘要翻译: 所述球墨铸铁构件具有主要由铁素体相组成且厚度为至少1mm的表层部分和由珠光体相和铁素体相组成的内部,所述表层部分具有铁素体相的铁素体相, 通过(a)将球状石墨铸造熔体注入铸模中来制造比内部部分大至少约15%的70%或更多的70% (b)在熔融物凝固完成之后通过摇晃除去铸模,同时基本上所得铸铁产品的整个部分仍处于其A1相变点或更高的温度; (c)当表面层与内部之间的温差变为40°-60°C时,将铸铁产品引入保持在750°-900℃的均匀炉中,铸件 铁产品保持这样一段时间,以便产生具有比内部部分大的铁素体比70%或更多的表层部分至少约15%的表面层部分; 和(d)将铸铁产品转移到冷却炉中,以15℃-100℃/ min的冷却速度冷却铸铁产品。

    Method of producing spheroidal graphite cast iron article
    2.
    发明授权
    Method of producing spheroidal graphite cast iron article 失效
    生产球墨铸铁制品的方法

    公开(公告)号:US5876523A

    公开(公告)日:1999-03-02

    申请号:US848022

    申请日:1997-04-28

    IPC分类号: C21D5/00 C22C37/04

    摘要: A method of producing a spheroidal graphite cast iron article containing at least one pearlite stabilizing element selected from the group consisting of Mn, Cu, Sn, Sb and Pb and having a double layer structure which comprises a surface layer portion and an inner portion. The surface layer portion has a matrix 60% or more of which is ferrite phase and a thickness of at least 0.5 mm. The inner portion has a matrix substantially comprising pearlite phase. The method comprises: (1) heat-treating a starting spheroidal graphite cast iron at a temperature which transforms a whole part of a matrix of the starting spheroidal graphite cast iron substantially to austenite phase; (2) slowly cooling the austenitized spheroidal graphite cast iron at a cooling rate (5.degree. to 20.degree. C./min) which allows in a subsequent step the surface layer portion to be ferritized before the inner portion starts to be pearlitized; (3) holding the cooled spheroidal graphite cast iron at a temperature (710.degree. to 770.degree. C.) which allows the surface layer portion to be first ferritized and subsequently allows the inner portion to be pearlitized while preventing the ferrite phase of the surface layer portion from being transformed to another; and (4) cooling the spheroidal graphite cast iron thus transformed immediately after completion of the pearlitization of the inner portion.

    摘要翻译: 一种球形石墨铸铁制品的制造方法,其特征在于,含有选自Mn,Cu,Sn,Sb,Pb中的至少一种珠光体稳定化元素,具有包含表层部分和内部的双层结构。 表层部分具有60%或更多的铁素体相和至少0.5mm的厚度的基体。 内部具有基本上包含珠光体相的基体。 该方法包括:(1)在起始球墨铸铁的基体的整个部分基本上转变为奥氏体相的温度下,对起始球墨铸铁进行热处理; (2)以冷却速度(5〜20℃/ min)缓慢冷却奥氏体化球墨铸铁,其允许在随后的步骤中,在内部部分开始被珠光化之前,表面层部分被铁素体化; (3)将冷却的球状石墨铸铁保持在温度(710℃至770℃),允许表面层部分首先铁素体化,随后允许内部部分被珠光化,同时防止表面层的铁素体相 部分转变为另一种; 和(4)在完成内部部分的珠光化之后立即冷却由此变形的球状石墨铸铁。