1. Stainless steel quality requirements
Stainless steel is a steel material with good corrosion resistance and has a wide range of applications. The quality requirements of stainless steel mainly include chemical composition, mechanical properties, appearance quality, etc.
1.Chemical composition
The chemical composition of stainless steel is mainly composed of chromium, nickel, molybdenum and other elements, of which the chromium content cannot be less than 10.5%. The chemical composition of stainless steel has an important impact on its corrosion resistance, heat resistance, mechanical properties, etc.
Hua steel company has own PMI machine,we can do PMI testing to check the stainless steel sheets and plates’ chemical composition more quickly.
2.Mechanical properties
The mechanical properties of stainless steel mainly include tensile strength, compressive strength, yield strength, elongation and other indicators. The mechanical properties of stainless steel materials directly affect its reliability and service life.
Every time, when we prepare the stainless steel products like sheets, coils, bars, pipes, we will send customer MTC, mill certificate ,which shows mechanical properties.
3. Appearance quality
The appearance quality of stainless steel refers to its surface quality requirements, which mainly include surface finish, surface condition, surface defects, etc. The qualification requirements for surface quality should comply with relevant standards.
As for the appearance quality, we will send whole products video and let our customer check the goods surface .
For Hua Steel Co.,surface appearance requirement as below:
(1)Hot-rolled thick steel plates, hot-rolled steel strips and coil-cut steel plates
Steel plates and steel strips are not allowed to have defects that may affect their use. The surface of pickled steel plates and steel strips is not allowed to have oxide scale or be over-pickled. It is allowed to grind and clean local defects on the surface of the steel plate, but the minimum thickness of the steel plate should be ensured.
A small number of abnormal parts of the steel strip are allowed.
(2)Cold-rolled steel strips and coil-cut steel plates
Steel plates should not have defects that would affect their use. It is allowed to have minor pitting, scratches, indentations, pits, roller marks and color differences with a depth less than half of the thickness tolerance that do not affect the use. Partial grinding is allowed, but the minimum thickness of the steel plate should be ensured.
The steel strip should not have defects that would affect its use. However, since there is generally no opportunity to remove defects in steel strips delivered in rolls, a small amount of abnormal parts are allowed. For unpolished steel strips, the surface is allowed to have slight pitting, scratches, indentations, pits, roller marks and color differences with individual depths less than half of the thickness tolerance.
The edges of the steel strip should be flat. The edge of the trimmed steel strip is not allowed to have uneven cutting with a depth greater than half the width tolerance and burrs greater than the thickness tolerance of the steel strip; the untrimmed steel strip is not allowed to have cracked edges greater than the width tolerance.
2. Stainless steel quality inspection and acceptance standards
1. Surface quality inspection
The surface quality inspection of stainless steel should be carried out by visual and manual inspection. Visual inspection should be carried out in a bright environment to check whether there are cracks, potholes, oxide scale, scratches and other defects on the surface. Use the hand touch method to check whether the surface is flat and smooth, and whether there are any defects such as bulges and depressions.
2. Mechanical property inspection
For purchased stainless steel materials, mechanical properties should be tested, including tensile strength, compressive strength, yield strength and other indicators. Mechanical property testing should comply with the requirements of relevant national standards and industry standards.
3. Determination of acceptance criteria
The quality acceptance standards for stainless steel materials are mainly based on its chemical composition, mechanical properties, surface quality and other requirements, and are judged with reference to relevant national and industry standards and specifications. The determination of acceptance standards should be strictly implemented to ensure the quality of stainless steel materials.
All of them , Hua steel company still welcome you come to visit our factory and check your goods by yourself ,That’s more perfectly!
