Cross-section macrostructure test pieces shall be etched and tested as per GB/T226,and they shall be free from visible shrinkage,bubble,crack and inclusion.The acceptable ratings are as follows:General porosilty≦class 2.0,central porosity ≦class 2.0,ingot setregation ≦class 2.0.
4.5 非金属夹杂物 Non-metallic inclusion
钢棒的非金属夹杂物按GB/T10561中的评级图评定,应符合表2的规定。
The non-metallic inclusion of steel bars shall be evaluated in accordance with GB/T10561,and the acceptable level shall conform to requirements of Table 2.
表2 非金属夹杂物要求
A类
Class A
B
Class B
C
Class C
D
Class D
细系
Thin
粗系
Heavy
细系
Thin
粗系
Heavy
细系
Thin
粗系
Heavy
细系
Thin
粗系
Heavy
≦1.5
≦0.5
≦1.5
≦1.0
≦1.0
≦1.5
≦1.5
≦1.5
4.6 晶粒度 Grain Size
交货状态的钢棒的晶粒度应按GB/T6394检验,晶粒度应不粗于6级。
The grain size of steel bars in the delivery condition shall be tested as per GB/T6394,and the grain size shall be no coarser than No.6.
4.7 机械性能 Mechanical property
交货状态钢棒的机械性能应符合表3的要求。
The mechanical property of steel bars in the delivery condition shall be as per requirements of Table 3.
Ultrasonic testing shall be performed in accordance with GB/T4162 for each piece of steel bar respectively with Class A acceptable for bars with the dimension of no more than 115mm and Class B acceptable for bars with the dimension ranging from 115mm to 250mm.
4.9 表面质量 Surface quality
钢棒表面不允许有任何裂纹、折叠、划伤等有影响使用的缺陷。
The surface of steel bars shall be free from any crack,loerlap,scratch and other defects that can influence the use of bars.