Billet quality appraisal

Steel billet refers to semi-finished steel that has gone through the smelting and casting process but has not been further processed. It is the basic raw material for the production of steel products and usually takes the form of large steel ingots or blocks of certain size and shape. Steel billets can be further processed into various steel products, such as plates, pipes, wire rods, etc.
The quality of steel billets directly affects the performance of the final steel product, so the production and quality control of steel billets is very important. During the production process of steel billets, the chemical composition, internal structure and surface quality need to be strictly controlled to ensure that they meet the requirements of subsequent processing and application.
In billet quality appraisal cases, Zhongke Testing can provide billet quality appraisal services.

can be divided into: rough rolled steel billets, small and medium-sized steel billets, forged steel billets, and continuous casting billets according to production methods.
can be divided into square billet, rectangular billet, thick slab, thin slab, strip billet, round tube billet and special-shaped billet according to the cross-sectional shape.
is divided into high-quality carbon steel round tube blanks, carbon steel hot-rolled square steel billets, axle steel billets for railway rolling stock, alloy structural steel round tube blanks and seamless tube blanks for high-pressure boilers according to steel types and uses.

GB/T 13447-2008 Steel billet for seamless gas cylinders
GB/T 24178-2009 Low magnification evaluation method of solidification structure of continuous cast steel billet
GB/T 37793-2019 Quantitative analysis method of dendrite segregation in steel billet
YB/T 4773-2019 Determination and calculation method of oxidation burning loss of steel billet
YB/T 4772-2019 Determination and calculation method of billet heating temperature uniformity
YB/T 4704-2018 Continuous casting special-shaped steel billet
TB/T 1027.1-2015 Locomotive axle Part 1: Steel billet
YB/T 4324-2013 Steel billet for high-speed and heavy-duty train axles
TB/T 2945-1999 LZ 50 steel axle and billet technical conditions for railway vehicles
YB/T 002-1991 Hot-rolled steel billet size, shape, weight and allowable deviation
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A steel factory ordered a batch of steel billets from a steel billet manufacturer to produce steel strips. After the steel billets were in place, the steel plant immediately started production. However, after the first batch of steel billets was put in, it was discovered that the steel strips produced had edge cracking and delamination problems. The scrap rate is close to 20%, which seriously affects the output quality. The billet manufacturer sent technicians to the site for confirmation, but failed to provide an effective solution. Because of repeated delays, the steel plant finally took it to court, hoping to resolve it through legal means.
was entrusted by a court to analyze the steel billet involved in the case that "caused edge cracking and delamination problems in the steel strip." Quality analysis results: The expert group randomly inspected the batch of steel billets. According to the identification plan, the samples were cut into 8 pieces and the cross-sectional shape was observed. It was found that all 8 samples had varying degrees of shrinkage cavities, cracks, subcutaneous bubbles and other problems. When the steel billet is hot-processed, the surface pores and subcutaneous bubbles are oxidized, causing the finished steel strip to fail to be welded and cracked.
It can be seen from this that the quality of this batch of steel billets has serious problems, does not meet the requirements of national standards, and is a substandard product.