How Much Do You Know About the Details of 15CrMo Seamless Steel Pipes Commonly Used in the Petroleum Industry

First, what are the material characteristics and core advantages of 15CrMo seamless steel pipes?

1. Chemical Composition and Mechanical Properties of 15CrMo Seamless Steel Pipes

Composition: Carbon content 0.12%-0.18%, Chromium: 0.80%-1.10%, Molybdenum: 0.40%-0.55%, belonging to low-alloy pearlitic heat-resistant steel.

Properties:

High-Temperature Strength: Tensile strength 440-640MPa, yield strength ≥235MPa, excellent creep strength below 500℃, temperature control required above 550℃.

Oxidation Resistance: A dense chromium oxide protective film forms on the surface, with a corrosion rate in sulfur environments only 1/3-1/2 that of carbon steel.

Hydrogen Corrosion Resistance: Suitable for hydrogen-containing media environments, reducing the risk of hydrogen-induced cracking.

2. What is the heat treatment process for 15CrMo seamless steel pipe?

Normalizing + Tempering: Normalizing temperature 900-960℃, tempering temperature 630-700℃, eliminating internal stress, optimizing microstructure (sorbite structure), and improving impact toughness (impact energy of heat-affected zone ≥47J).

Process stability: Controlled rolling and cooling technology ensures uniform performance, and online heat treatment reduces production costs.

Second, what are the applications of 15CrMo seamless steel pipe in the petrochemical and chemical industries?

1. What are the typical application scenarios for 15CrMo seamless steel pipe?

A) Petroleum cracking units:

Furnace tubes: Withstand high-temperature cracking reactions (temperature ≥500℃) and require long-term stable operation.

Heat exchanger tubes: Transport high-temperature fluids, requiring corrosion resistance and resistance to thermal fatigue.

Pressure pipelines: Connect critical equipment, requiring high strength and sealing.

B) Chemical equipment:

Hydrogenation reactors: High-pressure hydrogen environment, requiring resistance to hydrogen embrittlement and high-temperature strength.

Synthesis towers: Resistant to corrosive media (such as acidic gases), reducing material loss.

C) Power Industry:

Steam Turbine Main Steam Pipelines: These withstand long-term high-temperature steam (540-580℃), requiring high durability and strength.

Reheat Steam Pipelines: Optimize thermal efficiency and reduce energy loss.

D) Advantages of Manufacturing Ring-Shaped Parts:

Material Utilization: Compared to solid steel, seamless steel pipes can save 30%-50% of material when manufacturing ring-shaped parts (such as bearing rings and jack sleeves).

Simplified Processes: Reduced machining steps (such as drilling and boring) shorten production cycles.

Structural Strength: Hollow cross-section design enhances bending stiffness, suitable for high-load applications.

E) Military Equipment Applications:

Gun Barrels and Cannons: Utilizing high strength and heat resistance, they withstand the impact of high-temperature, high-pressure combustion gases, extending service life.

Hydraulic Systems: Manufacturing high-pressure hydraulic cylinders ensures sealing and reliability.

Third, what are the details of the manufacturing process and quality control of 15CrMo seamless steel pipes?

1. Production process details of 15CrMo seamless steel pipes:

Hot rolling: Round billets are heated to 1100-1200℃ and pierced and rolled, resulting in a dense structure suitable for mass production.

Cold drawing: Drawing at room temperature, resulting in high dimensional accuracy (outer diameter deviation ≤ ±0.2mm) and good surface finish (Ra≤0.8μm).

Hot expansion: Optimizing mechanical properties through multi-pass expansion to meet large-diameter requirements (large outer diameter 765mm).

2. Quality inspection methods for 15CrMo seamless steel pipes:

Non-destructive testing: Ultrasonic testing to detect internal defects (sensitivity ≥99.9%), eddy current testing to detect surface cracks.

Hydraulic pressure test: Verifying pressure-bearing capacity (pressure ≥ 1.5 times design pressure).

Metallographic analysis: Microstructure inspection (grain size rating ≥ 6), hardness testing (Brinell hardness ≤ 170HBW).