AISI ASTM Precision Steel Pipe 201 304 316 Cold Rolled Stainless Steel Material

Product Specification

Precision Stainless Steel Pipes Cold Rolled Steel Material 201 304 316 Stainless Steel Tube

Embrittlement phenomenon
According to the tempering temperature range of precision pipe brittleness, it can be divided into low temperature tempering brittleness and high temperature tempering brittleness.
After quenching martensitic structure of precision tube low temperature tempering brittle alloy steel, the steel embrittlement is made by tempering in the temperature range of 250 ~ 400℃, and the transformation temperature of toughness to brittleness is obviously increased. The embrittlement precision tube can no longer be eliminated by low temperature tempering heating, so it is also called % 26LDquo; Irreversible temper brittleness %26rdquo; . It mainly occurs in alloy structural steel and low alloy ultra-high strength precision pipe steel. The fracture of embrittlement precision tube is either intercrystalline fracture or intercrystalline and quasi cleavage fracture. The causes of low temperature tempering brittleness are generally considered as follows :(1) it is closely related to grain boundary embrittlement caused by the precipitation of cementite at the original austenite grain boundary during low temperature tempering. (2) The segregation of impurity elements such as phosphorus at the grain boundary of proto-austenite is also one of the reasons for tempering brittleness at low temperature. High purity precision tubes with phosphorus content less than 0.005% do not produce low temperature tempering brittleness. The austenite grain boundary segregation occurs when the phosphorus is heated by fire and remains after quenching. Phosphorus precipitates at proto-austenite grain boundary during segregation and cementite tempering. These two factors cause intergranular brittle fracture and contribute to the occurrence of low temperature tempering brittleness.

Alloy elements in precision tubes have great influence on tempering brittleness at low temperature. Chromium and manganese promote the segregation of impurity elements such as phosphorus at austenite grain boundaries, thus promoting low temperature tempering brittleness, tungsten and vanadium basically have no effect, molybdenum reduces the ductile-brittleness transition temperature of low temperature tempering precision tube, but it is not enough to inhibit low temperature tempering brittleness. Silicon can delay the precipitation of cementite during tempering and increase its formation temperature, so it can increase the temperature at which the brittleness of precision tube occurs at low temperature.

FAQ

Q1: Are you trading company or manufacturer ?
A:Yes, we are manufacturers. We have our own factory and our own company. I believe we will be the most suitable supplier for you.

Q2: How about your quality and how do you guarantee the quality?
A: All products we supply is primary as you need, Our company is certificated to ISO9001: 2008, and every product will be tested for 4-5 processes. We welcome customers or the third party inspection agencies to come to our factory for inspection.

Q3: Do you provide samples ? Is it free or extra ?
A: Yes, we could offer the Stainless Steel pipe sample for free charge.

Q4: How long is your delivery time?
A: For Stocks, we can send the goods to loading port within 7 days after receiving the deposit ;
For production period, it usually needs about 15 days ~30 days after receiving the deposit.

Q5: What is your terms of payment ?
A: Usually 30% deposit by TT in advance and balance against copy pf BL or L/C at sight.