KIA MS126-09 Cold Rolled Austenitic Stainless Steel Sheets and Coils

The “KIA MS126-09 Cold-rolled austenitic stainless steel sheet and coil” standard, developed by Hyundai-Kia Motors Company, the oldest motor vehicle manufacturer in Korea, describes the requirements for cold-rolled austenitic stainless steel sheet and coil.

The classification and notation of sheet and coil are shown in the table given in the standard.

The general requirements in this standard are described as follows:

• Cold rolled sheet and coil are processed by the corresponding process of annealing and pickling. In addition, tempering rolling, straightening and grinding can be done if necessary.
• The surface quality of the sheet and coil should be good and smooth enough to be free from defects that are detrimental to practical use. For steel coil, it is tolerable to have some irregular parts and welds because steel coil does not provide the opportunity to easily inspect and remove such defective parts.

The detailed requirements in this standard are explained as follows:

• Chemical composition: The chemical composition of the ladle analysis and the sheet and coil must comply with the values ​​given in the table titled “Chemical composition (percentage by weight)” given in the standard. The allowable tolerance of the product analysis must comply with the standard “KS D 0228 Product analysis and tolerance for forged steel”.
• Mechanical properties: The mechanical properties of the annealed sheet and coil must be in accordance with the table titled “Tensile test” given in the standard. In the case of bending test, there must be no cracks on the outer surface of the sample.
• Microstructure: The microstructure of annealed sheet and coil should not contain abnormal mixture of coarse particles, precipitates or non-metallic inclusions. The size number of crystal should be between 4~8 in principle. For bellows lock, the size of the number of 1.4828 crystal should be more than 7.
• Surface coating: The surface coating of sheets and coils must comply with the table given in the standard.
• Dimension and dimension tolerance: If not specified, the thickness tolerance of sheet and coil shall be in accordance with the thickness tolerance A value in the relevant table given in the standard. In the case of special specification, the thickness tolerance B value in the relevant table given in the standard shall be applied. The measurement shall be taken from any point 15 mm or more away from the edge. Meanwhile, the cutting paper tolerance, coil width tolerance and sheet flatness requirements shall be in accordance with the relevant tables given in the standard. Also, the coil camber requirements are as in the following table given in the standard. However, it shall not be applied to the remaining part of the coil including the first and last 1m roll. In terms of heavy metals and harmful substances, each material shall meet the standard “MS201-02 Prohibition and notification of the use of harmful substances - Parts and materials”.

In this standard, the analysis methods are specified as follows:

• KS D 1801 General rules for chemical analysis of iron and steel
• KS D 1652 Spark discharge atomic emission methods
• KS D 1650 General rules for photoelectric emission spectrochemical analysis of metallic materials
• KS D 1804 Methods for determination of carbon in iron and steel
• KS D 1805 Determination methods of silicon in iron and steel
• KS D 1806 Methods for determination of manganese in iron and steel
• KS D 1802 Determination methods of phosphorus in iron and steel
• KS D 1803 Methods for determination of sulfur in iron and steel
• KS D 1808 Methods for the determination of nickel in iron and steel
• KS D 1807 Methods for the determination of chromium in iron and steel
• KS D 1809 Methods for determination of molybdenum in iron and steel
• KS D 1810 Methods for determination of copper in iron and steel
• KS D 1876 Methods for the determination of titanium in iron and steel
• KS D 1811 Methods for determination of nitrogen in iron and steel
• KS D 1825 Methods for determination of niobium in iron and steel

In this standard, test methods are defined as follows:

• Tensile test: If not specified, the test piece shall be prepared in accordance with the standard “ISO 6892 Metallic materials - Tensile testing” or “KS B 0801 Test pieces for tensile testing of metallic materials” and tested parallel to the final rolling direction. The test method shall comply with these standards.
• Hardness test: The test procedure shall be in accordance with the standard “ISO 6507-1 Metallic materials - Vickers hardness test - Part 1: Test method” or “KS B 0811 Vickers hardness test method”. If not specified, the test piece from those taken for other tests shall be used.
• Microstructure test: The test piece should not be prepared separately, but should be used from those taken for other tests. The surface or cross section of the piece should be polished and then examined with a microscope after etching.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also testing services within the scope of the "KIA MS126-09 Cold-rolled austenitic stainless steel sheet and coil" standard.