Rockwell hardness judging method of thin-specification Cr-Ni system austenite stainless steel plate

Abstract

The invention provides a Rockwell hardness judging method of a thin-specification Cr-Ni system austenite stainless steel plate. The Rockwell hardness judging method is characterized by comprising the following steps of: (1) selecting two groups of products produced by one unit, wherein the thickness of each product in the first group is more than 1.50mm and the first group comprises at least 50 products; the thickness of each product in the second group is less than or equal to 1.50mm and the second group comprises at least 50 products; (2) testing the first group of products by using a method specified by Metal Material Rockwell Hardness Testing Method to obtain a hardness number HRB average value in production; (3) obtaining a metallic Vickers hardness number HV average by testing the second group of products according to Metal Material Vickers Hardness Test; and (4) judging by utilizing a formula HRB=HV / 1.98: if the HRB=HV / 1.98 meets goods ordering standard requirements, judging that the thin-specification Cr-Ni system austenite stainless steel plate is qualified; and if the HRB=HV / 1.98 does not meet the goods ordering standard requirements, judging that the thin-specification Cr-Ni system austenite stainless steel plate is unqualified. The Rockwell hardness judging method disclosed by the invention solves the difficulty of a thin sheet plate HRB test.

Description

technical field [0001] The invention is mainly used for determining the Rockwell hardness of thin Cr-Ni austenitic stainless steel plates with a thickness less than or equal to 1.50 mm. Background technique [0002] The Rockwell hardness (HRB) of austenitic stainless steel plate is the performance index required by customers in the US market. However, it was found in production that for thin-gauge Cr-Ni austenitic stainless steel plates (hereinafter referred to as: thin steel plates) with a thickness of ≤1.50mm, it is not possible to comply with GB / T230.1-2009 "Metallic Rockwell" due to the following reasons. Hardness Test Part 1: Test Method" for HRB test. [0003] First, when the thin-gauge Cr-Ni austenitic stainless steel plate is tested according to the method specified in GB / T230, there are visible deformation marks on the back of the sample, while 6.3 of GB / T230 stipulates: Except for HR30Tm, the sample after the test There should be no visible deformation on the bac...

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Problems solved by technology

[0005] Second, in GB / T1172 "Conversion Value of Hardness and Strength of Ferrous Metals", "Conversion Value of Carbon Steel Hardness and Strength", although HV and HRB hardness conversion is given Correspondence table, but only for mild steel

A large number of data in the production process prove that GB / T1172 is not suitable for hardness conversion of Cr-Ni austenitic stainless steel plate

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