Precipitation-hardening martensitic stainless steel 17-4PH smelting technology

A martensitic stainless steel, precipitation hardening technology, applied in the direction of process efficiency improvement, furnace type, furnace, etc., can solve the problems of not being able to adapt to the market demand for low gas and low inclusions, affecting product performance, etc., to reduce smelting time, Effects of avoiding stress cracks and reducing production costs

Active Publication Date: 2017-11-24
HENAN ZHONGYUAN SPECIAL STEEL EQUIP MFG CO LTD
View PDF6 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The usual 17-4PH smelting adopts the method of AOD decarburization, reduction and fine-tuning alloy tapping, weak stirring, and direct casting into electrode billets. Although carbon is effectively controlled in this production method, the content of H, O, and N in the steel High, generally H is 3-4ppm, oxygen is 20-40ppm, and N is between 100-200ppm, which seriously affects the performance of the product and cannot meet the market demand for low gas and low inclusions

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Precipitation-hardening martensitic stainless steel 17-4PH smelting technology
  • Precipitation-hardening martensitic stainless steel 17-4PH smelting technology

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0020] Precipitation hardening martensitic stainless steel 17-4PH smelting process, using the process route of EAF / IF-LF-VOD-LF-VD-IC, the composition is as follows: C≤0.07%, Si≤1.0%, Mn≤1.0%, P≤ 0.025%, S≤0.010%, Ni:3.00-5.00%, Cr:15.0-17.5%, Cu:3.00-5.00%, Nb:0.15-0.45%; the steps of the smelting process are as follows:

[0021] Step S01: Using steel scrap and pig iron with low five harmful elements as the raw material of the electric furnace, the electric furnace is melted and dephosphorized at low temperature in the early stage of oxidation to smelt molten steel with low phosphorus and five harmful elements, and the electric furnace taps steel [C]≤0.05%, [P] ≤0.003%, [As]≤0.010%, [Sn]≤0.006%, [Pb]≤0.005%, [Sb]≤0.005%, [Bi]≤0.005%, the tapping process is based on 2-3Kg aluminum iron per ton of steel Carry out deoxidation to avoid slag overflow;

[0022] Step S02: Use an intermediate frequency furnace to melt alloys such as ferrochromium, nickel, and copper plates, accordin...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention belongs to the field of stainless steel smelting, and particularly relates to a precipitation-hardening martensitic stainless steel 17-4PH smelting technology. The smelting technology comprises the steps that an EAF / IF-LF-VOD-LF-VD-IC technological route is adopted, and low-phosphorous and low-five-harmful-element primary smelting molten steel in a smelting electric furnace, medium-frequency melting alloy and electric furnace tapping steel are industrially blended and then enter an LF refining furnace for chemical component adjustment; drossing is conducted, VOD vacuum oxygen blowing and primary reduction are conducted, and then comprehensive reduction and alloy fine adjustment are conducted in a refining furnace; and VD degassing and mold-casting steel pouring are conducted, and 17-4PH stainless steel which is low in carbon, gas, impurity and five-harmful elements is produced. The invention aims at overcoming the detects that in the prior art, steel obtained in 17-4PH smelting is higher in H, O and N content, and the using property of products is seriously affected, and providing the low-gas-content and low-impurity precipitation-hardening martensitic stainless steel 17-4PH smelting technology.

Description

technical field [0001] The invention belongs to the field of stainless steel smelting, and in particular relates to a precipitation hardening martensitic stainless steel 17-4PH smelting process. Background technique [0002] As a typical precipitation hardening martensitic stainless steel, 17-4PH has good corrosion resistance and is widely used in offshore platforms, food manufacturing, aerospace and other fields. The usual 17-4PH smelting adopts the method of AOD decarburization, reduction and fine-tuning alloy tapping, weak stirring, and direct casting into electrode billets. Although carbon is effectively controlled in this production method, the content of H, O, and N in the steel Higher, generally H is 3-4ppm, oxygen is 20-40ppm, and N is 100-200ppm, which seriously affects the performance of the product and cannot meet the market demand for low gas and low inclusions. Contents of the invention [0003] The purpose of the present invention is to overcome the shortcom...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C21C5/52C21C7/064C21C7/06C21C7/068C21C7/10C22C33/04
CPCC21C5/005C21C5/52C21C7/06C21C7/064C21C7/0685C21C7/10C22C33/04Y02P10/20
Inventor 祁跃峰王志林赵鹏李立新金会业
Owner HENAN ZHONGYUAN SPECIAL STEEL EQUIP MFG CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products