ASTM A387 is a standard specification published by the American Society for Testing and Materials (ASTM) that covers chromium-molybdenum (Cr-Mo) alloy steel plates intended for welded pressure vessels and high-temperature service. These alloys are valued for their excellent high-temperature strength, creep resistance, and resistance to hydrogen-induced corrosion, making them critical in industries such as oil and gas, petrochemicals, power generation (especially thermal and nuclear), and chemical processing.

 

Below is a detailed breakdown of the most commonly used grades under ASTM A387: Grade 5, 9, 11, 12, 22, and 91.

Key Characteristics of ASTM A387 Alloys

All grades in ASTM A387 are designed for elevated-temperature service (typically above 300°C/572°F) and share core properties:

 

High tensile and yield strength at high temperatures.

Resistance to creep (slow deformation under sustained load at high temperatures).

Good weldability and formability (with proper pre/post-weld heat treatment).

Resistance to hydrogen attack and oxidation in harsh environments (e.g., hydrogen-rich or corrosive process streams).

Detailed Overview of Each Grade

1. ASTM A387 Grade 5

Alloy Composition (Typical): 5% Cr, 0.5% Mo (balance Fe, with minor elements like C, Mn, Si, P, S).

Key Properties:

Tensile strength: 415–585 MPa (60–85 ksi).

Yield strength: ≥205 MPa (30 ksi).

High chromium content enhances oxidation resistance, making it suitable for moderately high-temperature environments.

Heat Treatment: Normalized and tempered (typically 650–700°C/1200–1290°F).

Applications:

Pressure vessels in chemical processing (handling corrosive or oxidizing media).

Furnace components and heat exchangers operating at 400–500°C (752–932°F).

 

 

 

 

 

2. ASTM A387 Grade 9

Alloy Composition (Typical): 9% Cr, 1% Mo (with trace elements like C, Mn, Si).

Key Properties:

Tensile strength: 515–690 MPa (75–100 ksi).

Yield strength: ≥275 MPa (40 ksi).

Improved high-temperature strength compared to lower Cr grades; better oxidation resistance than Grade 11 or 12.

Heat Treatment: Normalized (900–980°C/1652–1796°F) + tempered (730–780°C/1346–1436°F).

Applications:

High-temperature boilers and steam pipes in power plants.

Pressure vessels for petrochemical processes involving high temperatures (up to 600°C/1112°F).

 

 

 

 

 

Why Choose Us?
We take pride in our ability to provide custom solutions for our customers' unique needs.
We analyze and compare the previous products and the current technical situation of our ASTM A387 GR. 5, 9, 11, 12, 22, 91 Alloy Steel Plate, and develop new technical specifications and processes.
Our customers trust us to deliver high-quality Cold-rolled Steel products on time and on budget.
We strictly implement the warm and thoughtful after-sales service, adhere to the development of good professional ethics.
We offer a wide range of Cold-rolled Steel products to meet diverse customer needs.
We adhere to the customer-centric and brand-oriented business philosophy, and continue to provide customers with reliable and excellent products and services.
Our factory is committed to upholding the highest standards of safety and quality.
All staff of our company and all departments work together to combine business management, professional technology, quantitative statistical methods and ideological education.
Our Cold-rolled Steel products are known for their durability and reliability.
Relying on the superior conditions and strong advantages of mass production, we are able to meet the different needs of our customers.

 

 

 

Hot Tags: astm a387 gr. 5, 9, 11, 12, 22, 91 alloy steel plate, China astm a387 gr. 5, 9, 11, 12, 22, 91 alloy steel plate suppliers, factory, GH3044, HastelloyC-4, Inconel825, N06625, N06690, N1 0665