What Items And Requirements Are Included In The Quality Inspection Of Stainless Steel Elbows
What items and requirements are included in the quality inspection of stainless steel elbows? Below, I will explain it in detail:
1. Stainless steel elbows in quenched state or after low-temperature tempering should be preheated, annealed or high-temperature tempered before repeated quenching;
2. Stainless steel elbows should be inspected according to the items and requirements specified in the corresponding technical documents;
3. The original records of heat treatment should be properly preserved for inspection;
4. When the stainless steel elbow fails to meet the requirements, it can be repeatedly heat treated, but the number of repeated quenching or solid solution generally does not exceed two times. Compensatory tempering of the workpiece is not counted as repeated treatment.
Stainless steel elbows are stainless steels with about half austenite and half ferrite structures. In the case of low C content, the Cr content is 18%~28%, and the Ni content is 3%~10%. Some steels also contain alloying elements such as Mo, Cu, Si, Nb, Ti, and N. This type of steel has the characteristics of both austenitic and ferritic stainless steel. Compared with ferrite, it has higher plasticity and toughness, no room temperature brittleness, no fear of intergranular corrosion, and significantly improved welding performance. At the same time, it also maintains the 475℃ brittleness of ferritic stainless steel and high thermal conductivity, and has the characteristics of superplasticity.
Stainless Steel Weld Elbow occupies an important position in pipelines, but stainless steel elbows are inevitably rusted after a long time of use. After rusting, it will not only damage the pipeline, but also cause leakage problems, which will cause serious problems. The economic loss is large, so stainless steel elbows should pay attention to rust prevention. Paying attention to stainless steel elbows can also extend their service life. However, the practice of stainless steel elbows in different regions is not the same. In the south of my country, the air is humid, which is hydrogen evolution corrosion in chemistry. Water is one of the substances that makes iron easy to rust, as long as the oxygen in the air dissolves. In water, oxygen reacts with iron in the water environment to produce something called iron oxide, which is rust. Rust is a brown-red substance. It is not as hard as iron. It is easy to fall off. If the rust is not removed, the spongy rust is particularly easy to absorb moisture, which will accelerate the corrosion of the stainless steel elbow.