HIGH-STRENGTH STEEL PLATE AND HIGH-STRENGTH STEEL PIPE EXCELLENT IN DEFORMABILITY AND LOW-TEMPERATURE TOUGHNESS, AND MANUFACTURING METHOD OF THE STEEL PLATEA high-strength steel pipe excellent in deformability and low-temperature toughness being a steel pipe obtained by a base steel plate formed into a pipe shape being welded, in which the base steel plate contains, in mass%, C: 0.010 to 0.080%, Si: 0.01 to 0.50%, Mn: 1.2 to 2.8%, S: 0.0001 to 0.0050%, Ti: 0.003 to 0.030%, B: 0.0003 to 0.005%, N: 0.0010 to 0.008%, O: 0.0001 to 0.0080%, one or more of Cr, Cu, and Ni, P: limited to 0.050% or less, Al: limited to 0.020% or less, Mo: limited to 0.03% or less, a Ceq obtained by (Expression 1) below of 0.30 to 0.53 and a Pcm obtained by (Expression 2) below of 0.10 to 0.20, and a balance being composed of iron and inevitable impurities, and a metal structure of the base steel plate contains 27 to 90% in area ratio of polygonal ferrite and a hard phase composed of one or both of bainite and martensite as its balance.A high-strength steel plate excellent in deformability and low-temperature toughness, comprising: in mass%, c: 0.010 to 0.080%; si: 0.01 to 0.50%; mn: 1.2 to 2.8%; s: 0.0001 to 0.0050%; ti: 0.003 to 0.030%; b: 0.0003 to 0.005%; n: 0.0010 to 0.008%; o: 0.0001 to 0.0080%; one or more of cr, cu, and ni; p: limited to 0.050% or less; al: limited to 0.020% or less; mo: limited to 0.03% or less; a ceq obtained by (expression 1) below of 0.30 to 0.53; and a pcm obtained by (expression 2) below of 0.10 to 0.20; and a balance being composed of iron and inevitable impurities; wherein a metal structure contains 27 to 90% in area ratio of polygonal ferrite and a hard phase composed of one or both of bainite and martensite as its balance. ceq=c+mn/6+ni+cu/15+cr+mo/5[image]pcm=c+si/30+mn+cu+cr/20+ni/60+mo/15+5⁢b[image] in (expression 1) and (expression 2) above, c, si, mn, ni, cu, cr, mo, and b denote the contents of the respective elements [mass%]. ni, cu, cr, and mo are calculated as 0 when the respective contents are 0%, wherein the high-strength steel plate excellent in deformability and low-temperature toughness optionally further comprises: one or two or more of, in mass%, w: 0.01 to 0.50%; v: 0.010 to 0.100%; nb: 0.001 to 0.200%; zr: 0.0001 to 0.0500%; ta: 0.0001 to 0.0500%; mg: 0.0001 to 0.0100%; ca: 0.0001 to 0.0050%; rem: 0.0001 to 0.0050%; y: 0.0001 to 0.0050%; hf: 0.0001 to 0.0050%; and re: 0.0001 to 0.0050%; wherein the ceq is obtained by (expression 1') below in place of (expression 1) above, and the pcm is obtained by (expression 2') below in place of (expression 2). ceq=c+mn/6+ni+cu/15+cr+mo+v/5[image]pcm=c+si/30+mn+cu+cr/20+ni/60+mo/15+v/10+5⁢b[image] in (expression 1') and (expression 2') above, c, si, mn, ni, cu, cr, mo, v, and b denote the contents of the respective elements [mass%]. ni, cu, cr, and mo are calculated as 0 when the respective contents are 0%. v is calculated as 0 when the content is 0% and the content is less than 0.010 mass%.
강판의 변형성과 저온강성 및 제조방법에 우수한 고강도 강판 및 고강도 강관변형성 및 저온 인성이 우수한 고강도 강관은 용접되는 배관형태로 형성된 강판에 의해 얻어진 강관으로, 그 강판에 질량% C: 0.010 ~ 0.080%, Si: 0.01 ~ 0.50%, Mn: 1.2 ~ 2.8%, S: 0.10001 ~ 0.00%가 포함되어 있다.10 ~ 0.008%, O: 0.0001 ~ 0.0080%, Cr, Cu 및 Ni 중 하나 이상, P: 0.050% 이하로 제한됨, Al: 0.020% 이하로 제한됨, Mo: 0.03% 이하로 제한됨, (Express 1), 0.30 ~ 0.53으로 구한 Ceq.Pm53.베이스 강판에는 폴리곤 페라이트 면적비 27~90%와 바이나이트와 마르텐사이트의 1개 또는 2개 모두로 구성된 경상이 포함되어 있다.변형성과 저온 인성이 우수한 고강도 강판. 질량% c: 0.010~0.080%, si: 0.01~0.50%, mn: 1.2~2.8%, s: 0.0001~0.0050%, ti: 0.003~0.3%, b: 0.00n%로 구성된다.20% 이하, mo: 0.03% 이하로 제한, 0.30~0.53 미만의 (이중 1)에 의해 얻어지는 ceq, 0.10~0.20 미만의 (이중 2)에 의해 얻어지는 PCM, 그리고 철과 불가피한 불순물로 구성되는 밸런스; 금속 구조물은 폴리곤 페라이트 면적 비율 27~90% 또는 둘 다 또는 둘 다로 구성된 상이다.흑연과 흑연석을 균형으로 하다. ceq=c+mn/6+ni+cu/15+cr+mo/5[이미지]는 (표현 1) 및 (표현 2) 위의 c, si, mn, ni, cu, cr, mo, b에서 각각의 요소들의 내용을 나타낸다. ni, cu, cr 및 mo는 각각의 함량이 0%일 때 0%로 계산되며, 여기서 변형성과 저온 인성이 우수한 고강도 강판은 선택적으로 추가로 구성된다: 질량, w: 0.01 ~ 0.50%, v: 0.010 ~ 0.100%, nb: 0.001 ~ 0.200%, zr: 0.000% ~ 0.0100%; ca: 0.0001 ~ 0.0050%, rem: 0.0001 ~ 0.0050%, y: 0.0001 ~ 0.0050%, re: 0.0001 ~ 0.0050%입니다. 여기서 ceq는 1의 위 및 1의 자리(수)에서 (수치)로 구합니다. ceq=c+mn/6+ni+cu/15+cr+mo+v/5[이미지]=c+si/30+mn+cu/20+ni/60+mo/15+v/10+5b[이미지] 위, c, si, mn, ni, cu, cr, mo, mo, b 내용물을 각각 나타낸다. ni, cu, cr, mo는 각각의 함량이 0%일 때 0으로 계산되며, v는 함량이 0%이고 0.010 질량% 미만이면 0으로 계산된다.