公开(公告)号：US5948183A

公开(公告)日：1999-09-07

申请号：US947388

申请日：1997-10-08

申请人： Susumu Okada ,  Masahiko Morita ,  Fumimaru Kawabata

发明人： Susumu Okada ,  Masahiko Morita ,  Fumimaru Kawabata

IPC分类号： C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/14

CPC分类号： C22C38/04 ,  C21D8/0226 ,  C22C38/02 ,  C22C38/12 ,  C22C38/14 ,  C21D2211/002 ,  C21D2211/005

摘要： The present invention provides a hot-rolled steel sheet having a low yield ratio, a high specific strength, and excellent toughness. The hot-rolled steel sheet comprises: 0.005 to less than 0.030 weight percent of carbon, 1.5 weight percent or less of silicon, 1.5 weight percent or less of manganese, 0.020 weight percent or less of phosphorus, 0.015 weight percent or less of sulfur, 0.005 to 0.10 weight percent of aluminum, 0.0100 weight percent or less of nitrogen, 0.0002 to 0.0100 weight percent of boron, at least one element selected from the group consisting of 0.20 weight percent or less of titanium and 0.25 weight percent or less of niobium in an amount to satisfy (Ti+Nb/2)/C.gtoreq.4, and balance iron and incidental impurities. The metal structure is selected from the group consisting of ferrite and bainitic ferrite. The amount of carbon dissolved in grains ranges from 1.0 to 4.0 ppm. The present invention also provides a method for producing a hot-rolled steel sheet. The method includes hot-rolling a steel slab containing the above components, cooling at a rate of between 5 to not more than 20.degree. C./sec., and then coiling at a temperature ranging from over 550.degree. C. to 700.degree. C.

摘要翻译： 本发明提供一种低屈服比，高比强度，优异的韧性的热轧钢板。 该热轧钢板包括：0.005〜小于0.030重量％的碳，1.5重量％以下的硅，1.5重量％以下的锰，0.020重量％以下的磷，0.015重量％以下的硫， 0.005〜0.10重量％的铝，0.0100重量％以下的氮，0.0002〜0.0100重量％的硼，至少一种选自钛的0.20重量％以下和0.25重量％以下的铌的元素 满足（Ti + Nb / 2）/ C> / = 4的量，并平衡铁和杂质。 金属结构选自铁素体和贝氏体铁素体。 溶解在谷物中的碳的量为1.0至4.0ppm。 本发明还提供一种热轧钢板的制造方法。 该方法包括对含有上述成分的钢板进行热轧，以不超过20℃/秒的速度冷却，然后在550℃〜700℃的温度下卷取 。

公开(公告)号：US4442340A

公开(公告)日：1984-04-10

申请号：US434379

申请日：1982-10-14

申请人： Fumimaru Kawabata ,  Atsushi Shiga ,  Tadamasa Yamaguchi

发明人： Fumimaru Kawabata ,  Atsushi Shiga ,  Tadamasa Yamaguchi

IPC分类号： B23K9/00 ,  B23K9/08 ,  B23K9/18

CPC分类号： B23K9/188

摘要： A four-electrode submerged arc welding process employs connections of four electrodes aligned in one row for alternating current source so that electromagnetic force Fx.sub.4 in a direction opposite to a welding direction acting upon a middle point of the arc from the rearmost electrode is within -25.ltorsim.Fx.sub.4 .ltorsim.-10 (N/m). The connections are preferably selected such that phase differences among currents applied to the three electrodes other than the frontmost or rearmost electrode are 120.degree., respectively, and a phase difference of the remaining frontmost or rearmost electrode is within 0.degree..+-.30.degree. relative to the furthermost electrode.With such connections of the four electrodes, the four-electrode submerged arc welding process remarkably prevents welding defects such as undercuts even at higher welding speeds.

摘要翻译： 四电极埋弧焊工艺采用一行排列的四个电极用于交流电源的连接，使得电磁力和上升沿与沿着最远的电极的电弧的中点作用的焊接方向相反的方向的Fx4在 - 25大概和上限和Fx4大概-10（N / m）。 优选选择连接，使得施加到除最前面或最后电极之外的三个电极的电流之间的相位差分别为120°，并且剩余的最前面或最后电极的相位差相对于0°+/- 30° 到最远的电极。 通过四个电极的这种连接，即使在较高的焊接速度下，四电极埋弧焊工艺也显着地防止焊接缺陷如底切。