LT-B2热轧圆钢技术协议
LT – B2 hot rolled round steel technical agreement
1、范围 Rang
本标准规定了磨球钢尺寸、外形、重量及允许偏差、技术要求、试验方法、检验规则、包装、标志和质量证明书等。
The provisions of this standard: The size, shape, weight and allowable deviation, technical requirements, test method, inspection rules, packing, mark, and quality certificate of grinding steel ball billet.
本标准适用直径和厚度不大于∮25-60mm规格的热轧圆钢。
This standard applies the diameter and thickness not more than ∮25-60mm hot rolled round steel.
2、引用标准 Quoted standard
GB/T222 钢的化学成分分析用式样取样法及成品化学成分允许偏差
GB/T222 Style sampling method for steel chemical composition analysis of the chemical components and finished products allow deviation
GB/T226 钢的低倍组织及缺陷酸蚀试验法
GB/T226 Steel macrostructure and defect of the acid corrosion test method
GB/T702 热轧圆钢和方钢尺寸、外形、质量及允许偏差
GB/T702 Hot rolled round steel and square steel size, shape, quality, and allowable deviation
GB/T1979 机构刚低倍组织缺陷评级图
GB/T1979 Macrostructure defect is just the rating figure
GB/T2101 型钢验收、包装、标志及质量证明书的一般规定
GB/T2101 Sections of the acceptance certificate, packing, marking, and quality general provisions
GB/T4336 碳素钢和中低合金钢光电发射光谱分析方法
GB/T4336 Carbon steel and low alloy steel photoelectric emission spectrum analysis method
ASTM E45 钢中非金属夹杂物含量测定方法
ASTM E45 The determination method of non-metallic inclusion content in steel
GB/T13299 钢的显微组织评定方法
GB/T13299 The steel microstructure evaluation methods
GB/T17505 钢及钢产品交货一般技术条件
GB/T17505 General technical conditions of delivery of steel and steel products
GB/T3077 合金结构钢
GB/T3077 structural alloy steel
3、尺寸、外形、重量 Size, Shape, Weight
-3.1热轧圆钢和方刚的尺寸、外形、重量及允许偏差应符合GB/T702中第二组的规定
The size, shape, weight, and allowable deviation of hot rolled round steel should match the stipulation of GB/T702 in the second group.
-3.2钢材定尺6米，末支直放。长度如有变化，合同中注明。
Steel scale 6 meters,
4、技术要求 Technical requirements
4.1牌号及化学成分 Grades and chemical component
4.1.1钢的牌号及化学成分（熔炼分析）应符合表1的规定。
The grades and chemical composition of steel should match the stipulation of table 1
钢的化学成分（占重量的百分比%）
Steel chemical component(The percentage of weight %)
|
Grade
|
C
|
Si
|
Mn
|
P
|
S
|
Cr
|
Ni
|
Cu
|
|
|
LT-B2
|
Max
|
0.86
|
0.35
|
0.80
|
0.035
|
0.035
|
0.60
|
/
|
0.25
|
|
Min
|
0.78
|
0.15
|
0.70
|
0.40
|
|||||
4.1.2钢材（或坯）的化学成分允许偏差按GB/T222中表2执行。
The chemical component allowable deviation of round steel(billet) is executed according to GB/T222 table 2
4.2冶炼方法 电炉/转炉+户外精炼真空去气
Smelting process electric furnace/converter+Outdoor vacuum refining to gas
4.3交货状态 Delivery condition
以热轧状态交货，作冷坑处理，并在合同中注明。钢坯到轧材压缩比>=10
Delivery at hot rolled condition, cold hole process, the compression ratio of steel billet>=10
4.4 低倍macro
4.4.1 钢材的横截面酸浸低倍组织试片不得有目视可见的缩空、气泡、裂纹、夹杂、翻皮、白点、晶间裂纹。
The cross-section of steel pickling macrostructure specimens can’t have visually visible contraction cavity, bubble, flaw, entrainment, skull patch, fisheye, intercrystalline crack
4.4.2 酸浸低倍组织合格级别应符合表2的规定
The qualified level of pickling macrostructure should match the stipulation of table 2
Table 2
|
center porosity（Grade）
|
General porosity（Grade）
|
Ingot shape segregation（Grade）
|
|
<=1.5
|
<=1.5
|
<=1.5
|
4.5 非金属夹杂物 nonmetallic inclusion
钢材应按ASTM E45进行非金属夹杂物检测，其合格级别应符合表3数据要求的规定。
Round steel should inspect according to ASTM E45, Its qualified grade should match the stipulation of table 3 parameter requirement.
Table 3
|
A
|
B
|
C
|
D
|
||||
|
Thin deparment
|
Thich department
|
Thin deparment
|
Thich department
|
Thin deparment
|
Thich department
|
Thin deparment
|
Thich department
|
|
<=2.5
|
<=2.5
|
<=2.5
|
<=2.5
|
<=2.5
|
<=2.5
|
<=2.5
|
<=2.5
|
4.6 金相组织metallographic structure
热轧状态组织不允许有贝氏体或马氏体存在。
Hot rolled state organizations are not allowed to bainite or martensite exists.
4.7 产品对钢坯所需的压缩比不得小于10
Products of billet required compression ratio shall not be less than 10
4.8 热顶锻合格 Hot upsetting qualified
4.9 表面质量：按GB/T3077-1999中6.6.1条规定执行，抽样酸洗确保。
Surface quality: According to GB/T3077-1999 Article 6.6.1 to execute, Sampling pickling ensure
5、实验方法experimental method
每批钢材的试验方法应按表4的规定执行。
Each batch of steel test method should be executed according to table 4
Table 4
|
S.N.
|
Inspection item
|
Sample number
|
Sampling location
|
Experimental method
|
|
1
|
化学成分Chemical component
|
1
|
GB/T222
|
GB/T223、GB/T4336
|
|
2
|
低倍 Macro
|
2
|
不同根钢坯或钢材Different billet or steel
|
GB/T226、GB/T1979
|
|
3
|
非金属夹杂物nonmetallic inclusion
|
2
|
不同根钢材Different billet or steel
|
ASTM E45
|
|
4
|
金相组织metallographic structure
|
1
|
任一根刚才
|
GB/T13299
|
|
5
|
尺寸Size
|
逐根One by one
|
整根钢材上
|
卡尺callipers、千分尺micrometer
|
|
6
|
表面质量Surface quality
|
逐根One by one
|
整根钢材上
|
目视visual
|
|
7
|
热顶锻
Hot upsetting
|
2
|
不同根钢材Different steel
|
GB/T233
|
6、检验规则Inspection stipulation
6.1 检查和验收check and accept
6.1.1 钢材出厂的检查和验收由供方质量技术监督部门进行。Steel factory inspection and acceptance conducted by the supplier quality and technical supervision department
6.1.2 供方必须保证交货的钢材符合本协议或合同规定。The supplier must ensure that delivery of steel in accordance with this agreement or contract
6.2 组织规则Organization Rule
钢材应按批检查和验收，每批由同一牌号、同一炉号、同一加工方法、同一尺寸、同一交货状态、同一热处理制度（炉次）的钢材组成。Steel should be according to the number of inspection and acceptance， Each batch should be composed of the same grade, the same furnace number, the same processing method, the same size, the same delivery condition, the same heat treatment system(melt)
6.3 取样数量和取样部位Sample quantity and sampling location.
每批钢材的取样数量和取样部位应符合表4的规定。
The sample quantity and sampling location of each batch of steel should accord with the stipulation of table 4.
6.4复验判定规则The reinspection decision rules
6.4.1钢材的复验与判定规则按GB/T17505规定执行
The reinspection decision rules of steel are executed according to GB/T17505
7、包装、标志、和质量证书 Packing, Mark and quality certificate.
钢材的包装、标志和质量证书应符合GB/T2101的有关规定。
The packing, mark, and quality certificate of steel should accord with the stipulation of GB/T2101
