摘要:
By using a plating bath containing chromic acid: 100 to 250 g/L, sulfate radical: 3.0 to 5.5 g/L, and a catalyst: 100 to 200% (a weight ratio to the chromic acid content) for conducting electroplating, a Cr-plating film which has an increased film crack density is formed on the surface of a mandrel bar base metal, whereby peeling-off of the Cr-plating film can be suppressed in mandrel mill rolling for extending the service life of the mandrel bar.
摘要:
A piercing and rolling plug has a film composed of oxides such as Fe3O4 and FeO and Fe (metal) as being formed on the surface of the base metal by electric arc spraying using an iron wire whose main component is Fe and, owing to this film, a plug excellent in heat-shielding and seizure-preventing effects can be realized and the lifetime of the plug can be prolonged. Further, in regenerating this plug, a film can be re-formed via the steps of shot blasting of the as-used plug in piercing and rolling and electric arc spraying in that order; thus, it is possible to regenerate the plug at low cost and in a short period of time.
摘要翻译:穿孔滚动塞具有由氧化物如Fe 3 O 4和FeO和Fe(金属)构成的膜,其通过使用主要成分为Fe的铁丝通过电弧喷涂形成在母材表面上,并且由于该膜 能够实现优良的隔热防止效果的塞子,延长塞子的使用寿命。 此外,在再生该插头时,可以通过以下步骤重新形成薄膜:依次进行穿孔和滚压以及电弧喷涂中使用的插头的喷丸处理; 因此,可以在低成本和短时间内再生插头。
摘要:
A continuously cast slab with a rectangular cross section, and made of high alloy containing Cr of 20 to 30 mass %, Ni of 30 to 50 mass %, and at least one of Mo and W as Mo+0.5W of 1.5 mass % or more is subjected to blooming and billet-making to yield a round bar having a diameter of 150 to 400 mm as a starting material of the seamless tube. The blooming and billet-making process is performed under a condition satisfying a relation of 1.3≦H/D≦1.8 where a short side length of the cross section of the cast slab is defined as H (mm), and the diameter of the round bar is defined as D (mm). The round bar is pierced-rolled to make a hollow blank; the hollow blank tube is elongation-rolled, and then diameter-adjusting-rolled to make the seamless tube, thereby preventing end cracking during piercing-rolling, and increasing yield.
摘要翻译:由具有20〜30质量%的Cr,30〜50质量%的Ni和Mo + 0.5W的Mo和W中的至少一种为1.5质量%的高合金构成的具有矩形截面的连续铸造板坯, 更多的是经受起霜和坯料生产,得到直径为150-400mm的圆棒作为无缝管的起始材料。 在满足1.3 @ H / D @ 1.8的关系的条件下进行起霜和坯料制造工艺,其中铸坯的横截面的短边长度被定义为H(mm),圆的直径 条被定义为D(mm)。 圆棒被穿孔轧制成中空的坯料; 中空坯管进行伸长轧制,然后进行直径调整轧制以制成无缝管,从而防止穿孔轧制过程中的端部开裂,并提高产量。
摘要:
A piercing mill includes a plurality of inclined rolls, a plug, a pusher, and an undriven guide roll. The pusher pushes a round billet from the rear end at least until the round billet advances for a prescribed distance after contacting the inclined rolls. The guide roll is between the inclined rolls and the pusher and includes a roll shaft and a roll surface, with the roll shaft arranged obliquely with respect to a pass line PL. The sectional shape of the roll surface is a concave arch shape. The round billet is rotated by the guide roll and the friction force generated when the round billet contacts the inclined rolls is reduced. Consequently, the wear of the inclined rolls can be restrained if the round billet is pierced and rolled while it is pushed in between the inclined rolls using the pusher.
摘要:
A piercing and rolling plug has a film composed of oxides such as Fe3O4 and FeO and Fe (metal) as being formed on the surface of the base metal by electric arc spraying using an iron wire whose main component is Fe and, owing to this film, a plug excellent in heat-shielding and seizure-preventing effects can be realized and the lifetime of the plug can be prolonged. Further, in regenerating this plug, a film can be re-formed via the steps of shot blasting of the as-used plug in piercing and rolling and electric arc spraying in that order; thus, it is possible to regenerate the plug at low cost and in a short period of time.
摘要翻译:穿孔滚动塞具有由氧化物如Fe 3 O 4和FeO和Fe(金属)构成的膜,其通过使用主要成分为Fe的铁丝通过电弧喷涂形成在母材表面上,并且由于该膜 能够实现优良的隔热防止效果的塞子,延长塞子的使用寿命。 此外,在再生该插头时,可以通过以下步骤重新形成薄膜:依次进行穿孔和滚压以及电弧喷涂中使用的插头的喷丸处理; 因此,可以在低成本和短时间内再生插头。
摘要:
A piercing mill includes a plurality of inclined rolls, a plug, a pusher, and an undriven guide roll. The pusher pushes a round billet from the rear end at least until the round billet advances for a prescribed distance after contacting the inclined rolls. The guide roll is between the inclined rolls and the pusher and includes a roll shaft and a roll surface, with the roll shaft arranged obliquely with respect to a pass line PL. The sectional shape of the roll surface is a concave arch shape. The round billet is rotated by the guide roll and the friction force generated when the round billet contacts the inclined rolls is reduced. Consequently, the wear of the inclined rolls can be restrained if the round billet is pierced and rolled while it is pushed in between the inclined rolls using the pusher.
摘要:
The present invention provides a lubricant composition for hot metal working which is capable of inhibiting generation of flaws on the surface of materials to be provided for hot metal working, and provides a method of hot metal working. The invention provides a lubricant composition for hot metal working comprising a plurality of glass frits respectively having different softening point from each other.
摘要:
a billet made of high Cr-high Ni alloy, which contains, by mass percent, 20 to 30% of Cr, 30 to 50% of Ni, and at least one element selected from Mo and W with a value “Mo+0.5W” of 1.5% or more is heated under conditions satisfying the following formula (1), and then the billet is pierced and rolled using an inclined roll type piercing mill with a roll gouge circumferential speed of 2.28 m/sec or higher. This prevents melted rash on the inner surface and lengthens the plug life. T≦1575−4.45×Vf−104.7×{−ln(th/ro)} (1) wherein T indicates a heating temperature (° C.) of the billet, Vf indicates the roll gouge circumferential speed (m/sec), ro indicates a radius (mm) of a billet at an entry-side, and th indicates a radial thickness (mm) of a pipe after piercing.
摘要:
By using a plating bath containing chromic acid: 100 to 250 g/L, sulfate radical: 3.0 to 5.5 g/L, and a catalyst: 100 to 200% (a weight ratio to the chromic acid content) for conducting electroplating, a Cr-plating film which has an increased film crack density is formed on the surface of a mandrel bar base metal, whereby peeling-off of the Cr-plating film can be suppressed in mandrel mill rolling for extending the service life of the mandrel bar.
摘要:
A plug material having a prescribed shape is prepared, the prepared plug material is thermally treated in a heat treatment atmosphere that contains at least 1.0 vol. % oxygen at a heat treatment temperature of at least 950° C. and less than 1050° C. and thus a plug having an oxide scale layer 30 on the surface is manufactured. According to the manufacturing method, pores PO that extend along the surface SF of the plug material are formed under outer scale layer 20 in the oxide scale layer 30, which allows cracks to be more easily propagated in the outer scale layer 20. Therefore, the outer scale layer 20 is more easily peeled off than the conventional one.