LSAW Steel Pipe

Submerged arc welded steel pipe (LSAW pipe or SSAW pipe) weld surface indentation refers to a weld defect in which the weld surface is partially lower than the normal surface of the weld, and is a common weld surface defect in submerged arc welding. In the production of submerged arc welded steel pipes, the weld seam is usually relatively long. Especially in the production of one-step spiral submerged arc welded steel pipes, it is often the case that thousands of meters of submerged arc welds are welded at one time, so it is relatively easy to produce pits on the surface of the weld. Hazards of indentation on weld surface 1. If the depth of the indentation on the surface of the weld is > 1.5mm, it must be treated as a weld defect. Once a steel pipe has several weld pits lower than the base metal, it is easy to cause the steel pipe to be degraded or even scrapped, and at least it will increase the repair cost of the steel pipe production. 2. Due to the wide application of 3PE externa...

Last week, domestic scrap steel prices rose and fell each other, and merchants became more afraid of falling and actively shipped goods. There were not many resources left on the site. The arrival of steel mills increased compared with the previous week. Some key steel companies adjusted their purchase prices according to their own conditions. Compared with the previous week, the average purchase price of scrap for key steel enterprises has increased by RMB 4/ton for heavy scrap, decreased by RMB 19/ton for medium-sized scrap, and increased by RMB 4/ton for aggregate scrap. Recently, the policy of restricting production and electricity has become stricter, the output and demand for finished products have weakened, and the profits of steel mills have been compressed. Affected by this, scrap prices have declined slightly in some areas. At present, most steel mills have delivered scrap steel to meet daily consumption, and their inventories are mostly maintained at a medium level. At the s...

Crude steel output continued to decline year-on-year. Since July, crude steel output has maintained a year-on-year decline for three consecutive months. According to the National Bureau of Statistics, in September, the national crude steel output was 73.75 million tons, down 21.2% year-on-year; the pig iron output was 65.19 million tons, down 16.1% year-on-year; the steel output was 101.95 million tons, down 14.8% year-on-year. From January to September, the country’s cumulative crude steel output was 806 million tons, a year-on-year increase of 2.0%; the cumulative pig iron output was 671 million tons, a year-on-year decrease of 1.3%; the cumulative steel output was 1.020 billion tons, a year-on-year increase of 4.6%. 2. Steel prices fluctuate at a high level. Steel prices remained high, but generally stable. According to data from the China Iron and Steel Association, at the end of September, the domestic steel composite price index was 157.70 points, up 4.4% month-on-month and 48.8%...

Looking at the development of the production of refractory materials across the country, it has gradually increased from about 74,000 tons in 1949 to a peak of 29,496,900 tons in 2011. The peak plateau period was in 2012 and 2013, and it dropped to about 28 million tons in 2014. In 2017, the lowest in recent years was about 23 million tons, and it fluctuated around 24 million tons in the past three years. Excluding infrastructure and exports, the total amount of domestic expendable refractories has been on the decline since 2011. In 2020, the total amount of expendable refractories in the iron and steel industry has dropped to about 14 million tons, plus the total amount of refractory materials consumed by cement, glass, ceramics, non-ferrous metals, coal chemical industries and other industries is about 20 million tons. It can be considered that China's refractory industry as a whole achieved its carbon peak in 2011. In the past ten years, the output of demand-side industries (ste...

Refractory material consumption per ton of steel decreased from 35kg~40kg in the early stage of reform and opening up to 25kg~30kg in the late 1990s, and then to 13kg~14kg in early 2021. Reduced to the international leading level of about 9kg. There are mainly the following 4 reasons: First, the iron and steel industry continues to adopt internationally advanced large-scale process technology and equipment, as well as modern and intelligent compact manufacturing process technology. The second is the simultaneous development of the refractory industry and the iron and steel industry; the variety and quality of refractory materials have reached the international advanced level, and the proportion of amorphous materials and the application of secondary resources have continued to increase. The third is the widespread use of advanced, high-efficiency and low-consumption technologies. For example, high-pass iron content iron ditch self-flowing castable and repair technology, ladle lining in...