Surface requirements of SSAW steel pipe

Currently, many steel pipe manufacturers face challenges with the surface quality of SSAW steel pipes(spiral submerged arc welded pipe), as the production and processing often fail to meet standard requirements. Below are some important surface quality requirements for SSAW steel pipes that manufacturersand purchasers need to be aware of.

Although the standards specify the expected “surface finish” for SSAW steel pipes, various factors during production can lead to up to 10 distinct surface issues. These problems primarily include: surface cracks, hairline cracks, internal and external folds, roll marks, internal and external straight channels, delamination, scabs, dents, bulging, pitting, abrasion, internal and external spiral channels, green lines, concave corrections, and others.

Among these issues, some, such as cracks, internal and external folds, roll marks, delamination, scabs, bulging, and severe pitting, are considered hazardous and can significantly impact the performance of the steel pipe. These are categorized as "critical problems." Others, like minor surface pitting, green lines, light abrasion, or slight internal and external straight or spiral channels, have a relatively smaller direct impact on the performance of the pipe and are referred to as "conventional problems."

Although minor conventional issues may not severely affect the functionality of the SSAW steel pipe, standards still impose strict limitations on the depth and size of these defects.

For hazardous problems, the standard approach is to completely remove them through excision or regrinding. When regrinding is allowed, the depth and shape of the affected areas must adhere to specific criteria. To enhance the overall surface quality, manufacturers sometimes apply treatments such as shot blasting, sand grinding, or machining turning to both the internal and external surfaces of the pipe.