Is There a Maximum Hardness Limit for AISI 4130 Q&T?

Introduction

Inquiry asks if there is a maximum hardness limit for AISI 4130 Q&T with a yield of 140 ksi for temperatures above 80°C in Table A.3. This inquiry pertains to NACE MR0175/ISO 15156-2 A.2.2.3.3, Table A.2, and Table A.3. Reference is made to ISO 15156 Maintenance Panel Inquiry #2016-06.

Background

AISI 4130 Q&T is a type of steel that is commonly used in the oil and gas industry. It is known for its high strength and toughness, making it ideal for use in harsh environments. However, there are concerns about the maximum hardness limit for this steel, particularly at high temperatures.

NACE MR0175/ISO 15156-2 A.2.2.3.3, Table A.2, and Table A.3

NACE MR0175/ISO 15156-2 is a standard that provides guidelines for the selection and use of materials in oil and gas production. Table A.3 of this standard lists the maximum hardness limits for various materials, but AISI 4130 Q&T is not included in this table.

Response

The response to the inquiry clarifies that AISI 4130 Q&T is not listed in Table A.3 of NACE MR0175/ISO 15156-2. However, the inquiry pertains to Table A.2, which provides guidelines for the use of materials in sour service environments. The response recommends that the maximum hardness limit for AISI 4130 Q&T in sour service environments should be determined based on the specific conditions of the application.