因切割不良造成的各种缺陷统称切割缺陷。其中热状态下用飞剪剪切小型钢材时,在钢材表面上造成深浅不一,外形不规则的伤痕称切伤;在热状态下,表面被锯片损伤称锯伤;经切割后,切割面与纵轴不垂直称切斜或锯斜;轧件端部热轧拉缩部分未切净称切头短;冷剪后,在剪切面上呈现局部小裂口叫撕裂;锯(剪)切后,留在钢材端面上的金属飞边称毛刺。
All kinds of defects caused by poor cutting are collectively referred to as cutting defects. When cutting small steel with flying shear in hot state, the scars with different depth and irregular shape on the steel surface are called cutting wounds; In the hot state, the surface is damaged by the saw blade, which is called sawing injury; After cutting, the cutting surface is not perpendicular to the longitudinal axis, which is called cutting inclination or sawing inclination; The cut head is short if the hot-rolled shrinkage part at the end of the rolled piece is not cut clean; After cold shearing, local small cracks appear on the shear surface, which is called tearing; After sawing (shearing), the metal flash left on the steel end face is called burr.
产生原因
Cause
锯切钢材与锯片(剪刃)不垂直或轧件头部弯曲过大;设备方面:锯片瓢曲度大,锯片磨老或安装不当、上下两剪刃间隙过大;飞剪失调;操作方面:同时剪切(锯切)钢材根数太多,端部切除太少,热轧拉缩部分未切净,以及各种误操作。
The sawing steel is not perpendicular to the saw blade (cutting edge) or the head of the rolled piece is bent too much; Equipment: the saw blade has a large curvature, the saw blade is worn or improperly installed, and the gap between the upper and lower blades is too large; Flying shear imbalance; Operation: too many steel pieces are cut (sawed) at the same time, too few ends are cut, the hot-rolled shrinkage part is not cut clean, and various misoperations.
控制方法
Control method
改善来料状况,采取措施,避免轧件头部弯曲过大,保持来料方向与剪(锯)切平面垂直;改善设备状况,采取无瓢曲或瓢曲度小的锯片,适当选择锯片厚度,锯片(剪刃)磨损要及时更换,正确安装、调整剪(锯)切设备;加强操作,同时剪(锯)切根数不要太多,避免钢材起落、弯曲。必须保证必要的端部切除量,将热轧拉缩部分切净,避免各种误操作。
Improve the incoming material condition, take measures to avoid excessive bending of the rolled piece head, and keep the incoming material direction perpendicular to the shear (SAW) cutting plane; Improve the condition of the equipment, adopt the saw blade without bending or with small bending degree, properly select the thickness of the saw blade, replace the saw blade (cutting edge) in time when it is worn, and correctly install and adjust the cutting (sawing) equipment; Strengthen the operation, and do not cut too many pieces at the same time to avoid the rise and fall and bending of steel. The necessary end cutting amount must be ensured to cut the hot-rolled shrinkage part completely to avoid various misoperations.
型钢矫痕--在冷矫过程中造成的表面伤痕。这种缺陷无热加工痕迹,多有一定规律性,主要有三种类型。凹坑型(或矫坑)、鱼鳞型、伤坏型。
Section steel correction marks -- surface scars caused in the process of cold correction. This kind of defect has no trace of hot working and has a certain regularity. There are three main types. Pit type (or correction pit), fish scale type, damaged type.
产生原因
Cause
矫直辊孔型过浅,矫直前钢材弯曲严重,矫直时喂钢不正或矫直机调整操作不当,可造成伤坏型矫痕;矫直辊局部损伤或粘结金属块、辊面局部凸起、矫直辊磨损严重或辊面温度高,粘结金属,可在钢材表面产生鱼鳞形矫痕。
The pass of the straightening roll is too shallow, the steel is seriously bent before straightening, the steel feeding is not correct during straightening or the straightening machine is adjusted improperly, which can cause damage to the straightening mark; The local damage of the straightening roll or the bonding metal block, the local bulge of the roll surface, the serious wear of the straightening roll or the high temperature of the roll surface, and the bonding metal can produce fish scale correction marks on the steel surface.
Jinan section steel gives you reference control methods
矫直辊磨损严重,矫痕严重时,不要继续使用;矫直辊局部损伤或粘接金属块时,要及时打磨光洁;矫直角钢等型钢时,因矫直辊和钢材接触表面相对运动较大(线速度差造成),易使矫直辊温度升高而刮瘤子,在钢材表面上产生矫痕,故应在矫直辊表面浇冷却水冷却;改进矫直辊材质或对矫直表面淬火,提高表面硬度,增加耐磨性。
Do not continue to use the straightening roll when it is seriously worn and has serious straightening marks; When the straightening roll is locally damaged or bonded with metal blocks, it should be polished and polished in time; When straightening steel sections such as angle steel, due to the relatively large movement of the contact surface between the straightening roll and the steel (caused by the linear speed difference), it is easy to raise the temperature of the straightening roll and scrape the tumor, resulting in straightening marks on the steel surface, so the surface of the straightening roll should be poured with cooling water for cooling; Improve the material of straightening roll or quench the straightening surface to improve the surface hardness and wear resistance.
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