Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nippon Steel & Sumikin Stainless Steel Corporation

Takashi Morohoshi

Masafumi Miyazaki

Takeshi Kubota

Masafumi Zeze

Masaharu Ueda

Takeaki Wakisaka

Kazutoshi Takeda

Masayuki Abe

Takashi Aramaki

Takuya Matsumoto

Junichi Hamada

Koji Fujita

Yoshiaki Natori

Akira Kobayashi

Ken Kimura

Akihiko Takahashi

Hiroyoshi Yashiki

Masaharu Oka

Kenichiro Miyamoto

Yuji Koyama

Hiroshi Sugano

Toyohiko Kakihara

Susumu Mukawa

Yoshihito Yamada

Yasuhiro Kinari

Shintaro Kusunoki

Ryusuke Miura

Satoshi Hashimoto

Koichiro Matsushita

Kazuo Fujita

Koichi Uchino

Takeshi Yamamoto

Hidekuni Murakami

Tomoji Kumano

Teruhisa Miyazaki

Katsuya Iwano

Ryutaro Kawamata

Kazunori Seki

Shinichi Kanao

Ken-ichi Murakami

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: 0.0003% or greater and less than 0.0015% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R&#x2212;(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: greater than 0.0100% and not greater than 0.0250% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R=(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: 0.0015% to 0.0100% in total, a parameter Q represented by Q=[Si]+2&#xd7;[Al]&#x2212;[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R=(I+I+I+I)/(I+I+I+I) is 0.80 or greater.

A non-oriented electrical steel sheet according to an aspect of the present invention contains, as a chemical composition, by mass %, C: more than 0% and 0.0050% or less, Si: 3.0% to 4.0%, Mn: 1.2% to 3.3%, P: more than 0% and less than 0.030%, S: more than 0% and 0.0050% or less, sol. Al: more than 0% and 0.0040% or less, N: more than 0% and 0.0040% or less, one or more of La, Ce, Pr, and Nd: 0.0005% to 0.0200% in total, Ca: 0.0005% to 0.0100%, Ti: 0.0005% to 0.0100%, Sn: 0% to 0.10%, Sb: 0% to 0.10%, Mg: 0% to 0.0100%, and a remainder including Fe and impurities, in which Si&#x2212;0.5&#xd7;Mn: 2.0% or more, and Si+0.5&#xd7;Mn: 3.8% or more.

Non-oriented electrical steel sheet

A non-oriented electrical steel sheet contains, as a chemical composition, by mass %, C: more than 0% and 0.0050% or less, Si: 3.0% to 4.0%, Mn: 1.0% to 3.3%, P: more than 0% and less than 0.030%, S: more than 0% and 0.0050% or less, sol. Al: more than 0% and 0.0040% or less, N: more than 0% and 0.0040% or less, O: 0.0110% to 0.0350%, Sn: 0% to 0.050%, Sb: 0% to 0.050%, Ti: more than 0% and 0.0050% or less, and a remainder including Fe and impurities, in which Sn+Sb: 0.050% or less, Si&#x2212;0.5&#xd7;Mn: 2.0% or more, and an O content in a sheet thickness central portion excluding a surface layer portion which is a range from a front surface and a rear surface to a position of 10 &#x3bc;m in a depth direction is less than 0.0100%.

When a Si content (mass %) is set to [Si], an Al content (mass %) is set to [Al], and a Mn content (mass %) is set to [Mn], a parameter Q represented by 'Q=[Si]+2[Al]&#x2212;[Mn]' is 2.00 or more, the total mass of S contained in sulfides or oxysulfides of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, or Cd is 40% or more of the total mass of S contained in a non-oriented electrical steel sheet, a {100} crystal orientation intensity is 3.0 or more, a thickness is 0.15 mm to 0.30 mm, and an average crystal grain diameter is 65 &#x3bc;m to 100 &#x3bc;m.

When a Si content (mass %) is set to [Si], an Al content (mass %) is set to [Al], and a Mn content (mass %) is set to [Mn], a parameter Q represented by 'Q=[Si]+2[Al]&#x2212;[Mn]' is 2.00 or more, the total mass of S contained in sulfides or oxysulfides of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, or Cd is 10% or more of the total mass of S contained in a non-oriented electrical steel sheet, a {100} crystal orientation intensity is 3.0 or more, a thickness is 0.15 mm to 0.30 mm, and an average crystal grain diameter is 65 &#x3bc;m to 100 &#x3bc;m.

A steel sheet according to the present invention includes a predetermined chemical composition, in which amounts of each elements by mass % in the chemical composition satisfy both of expression '0.3000&#x2264;{Ca/40.88+(REM/140)/2}/(S/32.07)' and expression 'Ca&#x2264;0.0058&#x2212;0.0050&#xd7;C', and a number density of carbonitrides including Ti which exists independently and has a long side of 5 &#x3bc;m or more is limited to 5 pieces/mmor less.

Steel sheet

In the rail, 95% or more of a structure in a head surface section, which is a range from surfaces of head corner sections and a head top section of the rail as a starting point to a depth of 20 mm, is a pearlite or bainite structure and the structure contains 20 to 200 MnS-based sulfides formed around an Al-based oxide as a nucleus and having a grain size in a range of 1 &#x3bc;m to 10 &#x3bc;m per square millimeter of an area to be inspected on a horizontal cross section of the rail.

Rail

Disclosed is a steel sheet in which the amounts of respective elements in chemical components, which are represented by mass %, satisfy the following Expression 1 and Expression 2. In addition, the steel contains Ti-included-carbonitrides as inclusions, and the number density of the Ti-included-carbonitrides having a long side of 5 &#x3bc;m or more is 3 pieces/mmor less.0.3&#x2266;{Ca/40.88+(REM/140)/2}/(S/32.07)&#x2003;&#x2003;(Expression 1)Ca&#x2266;0.005&#x2212;0.0035&#xd7;C&#x2003;&#x2003;(Expression 2).

The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions &#x3c;2&#x3e; and &#x3c;3&#x3e;,17.4(AlO)+3.9(MgO)+0.3(MgAlO)+18.7(CaO)&#x2266;500&#x2003;&#x2003;&#x3c;2&#x3e;,(AlO)+(MgO)+(MgAlO)+(CaO)&#x2267;95&#x2003;&#x2003;&#x3c;3&#x3e;.

Ferritic stainless steel casting and sheet and method for producing the same

This pearlitic rail consists of a steel including: in terms of percent by mass, C: 0.65% to 1.20%; Si: 0.05% to 2.00%; Mn: 0.05% to 2.00%; and REM: 0.0005% to 0.0500%, with the balance being Fe and inevitable impurities, wherein, in a head portion of the rail, a head surface portion which ranges from surfaces of head corner portions and a head top portion to a depth of 10 mm has a pearlite structure, and the hardness Hv of the head surface portion is in a range of 320 to 500.

Pearlitic rail with excellent wear resistance and toughness

The present invention is: a pearlitic steel rail excellent in wear resistance and ductility, characterized in that, in a steel rail having pearlite structure containing, in mass, 0.65 to 1.40% C, the number of the pearlite blocks having grain sizes in the range from 1 to 15 &#x3bc;m is 200 or more per 0.2 mmof an observation field at least in a part of the region down to a depth of 10 mm from the surface of the corners and top of the head portion; and a method for producing a pearlitic steel rail excellent in wear resistance and ductility, characterized by, in the hot rolling of said steel rail, applying finish rolling so that the temperature of the rail surface may be in the range from 850&#xb0; C. to 1,000&#xb0; C. and the sectional area reduction ratio at the final pass may be 6% or more, and then applying accelerated cooling to the head portion of said rail at a cooling rate in the range from 1 to 30&#xb0; C./sec. from the austenite temperature range to at least 550&#xb0; C.

Growing community of inventors

Tokyo, Japan

Takashi Morohoshi